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Sample records for 2-5 times greater

  1. TWOS - TIME WARP OPERATING SYSTEM, VERSION 2.5.1

    NASA Technical Reports Server (NTRS)

    Bellenot, S. F.

    1994-01-01

    The Time Warp Operating System (TWOS) is a special-purpose operating system designed to support parallel discrete-event simulation. TWOS is a complete implementation of the Time Warp mechanism, a distributed protocol for virtual time synchronization based on process rollback and message annihilation. Version 2.5.1 supports simulations and other computations using both virtual time and dynamic load balancing; it does not support general time-sharing or multi-process jobs using conventional message synchronization and communication. The program utilizes the underlying operating system's resources. TWOS runs a single simulation at a time, executing it concurrently on as many processors of a distributed system as are allocated. The simulation needs only to be decomposed into objects (logical processes) that interact through time-stamped messages. TWOS provides transparent synchronization. The user does not have to add any more special logic to aid in synchronization, nor give any synchronization advice, nor even understand much about how the Time Warp mechanism works. The Time Warp Simulator (TWSIM) subdirectory contains a sequential simulation engine that is interface compatible with TWOS. This means that an application designer and programmer who wish to use TWOS can prototype code on TWSIM on a single processor and/or workstation before having to deal with the complexity of working on a distributed system. TWSIM also provides statistics about the application which may be helpful for determining the correctness of an application and for achieving good performance on TWOS. Version 2.5.1 has an updated interface that is not compatible with 2.0. The program's user manual assists the simulation programmer in the design, coding, and implementation of discrete-event simulations running on TWOS. The manual also includes a practical user's guide to the TWOS application benchmark, Colliding Pucks. TWOS supports simulations written in the C programming language. It is designed

  2. Time Warp Operating System, Version 2.5.1

    NASA Technical Reports Server (NTRS)

    Bellenot, Steven F.; Gieselman, John S.; Hawley, Lawrence R.; Peterson, Judy; Presley, Matthew T.; Reiher, Peter L.; Springer, Paul L.; Tupman, John R.; Wedel, John J., Jr.; Wieland, Frederick P.; Younger, Herbert C.

    1993-01-01

    Time Warp Operating System, TWOS, is special purpose computer program designed to support parallel simulation of discrete events. Complete implementation of Time Warp software mechanism, which implements distributed protocol for virtual synchronization based on rollback of processes and annihilation of messages. Supports simulations and other computations in which both virtual time and dynamic load balancing used. Program utilizes underlying resources of operating system. Written in C programming language.

  3. Monitoring PM2.5 in the Atmosphere by Using Terahertz Time-Domain Spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhan, Honglei; Zhao, Kun; Bao, Rima; Xiao, Lizhi

    2016-09-01

    The real-time monitoring of the air pollution with multiple sources is of great significance for pollution control and environmental protection. In this paper, we presented a study of terahertz time-domain spectroscopy (THz-TDS) as a direct tool for monitoring the component and content of PM2.5 in atmosphere. Due to the THz absorption, the intensities of the peaks in THz-TDS decreased with the augment of PM2.5 and were proportional to the PM2.5 content. The ratio of absorbance A to PM2.5 reflected a basically unchanged tendency, indicating the little change of principal elements under the pollution degree. In the high-pollution condition, a lot of SO2 from vehicle and factory was emitted into air. The elements, such as S and O from anions, had a stronger absorption effect in THz range. Based on the absorbance spectra, the absorption tendencies with PM2.5 over the whole range were validated by principal component analysis and the quantitative model with a high correlation was built by using back propagation artificial neural network. BPANN model improved the precision of linear fitting between peak intensities and PM2.5. The research demonstrates that THz-TDS is a promising tool for fast, direct, and reliable monitoring in environmental applications.

  4. Time Course of Heart Rate Variability Response to PM2.5 Exposure from Secondhand Smoke

    PubMed Central

    Garza, Jennifer L.; Mittleman, Murray A.; Zhang, Jinming; Christiani, David C.; Cavallari, Jennifer M

    2016-01-01

    Purpose: Exposure to secondhand smoke (SHS) has been associated with decreased heart rate variability (HRV). However, the time course of this association is unclear. Therefore, the objective of this study was to investigate the association between 15–240 minute SHS-related fine particulate matter (PM2.5) moving averages and indices of HRV. Methods: With a panel study design, we used personal monitors to continuously measure PM2.5 and HRV of 35 participants who were exposed to SHS for approximately 6 hours. Results: We observed negative, significant associations between 5-minute HRV indices and 15 minute PM2.5 moving averages and 240 minute PM2.5 moving averages: there was a significant (p<0.01) 7.5% decrease in the 5-minute square root of the mean squared differences of successive normal heart beats associated with (RMSSD), and a significant (p<0.01) 14.7% decrease in the 5-minute high frequency (HF) power associated with the 15 minute PM2.5 moving averages; there was also a significant (p<0.01) 46.9% decrease in the 5-minute RMSSD, and a significant (p<0.01) 77.7% decrease in the 5-minute high frequency (HF) power associated with the 240 minute PM2.5 moving averages. Conclusions: Our findings that exposure to SHS related PM2.5 was associated with HRV support the hypothesis that SHS can affect the cardiovascular system. The negative associations reported between short and longer term PM2.5 and HRV indicate adverse effects of SHS on the cardiovascular system. PMID:27223894

  5. Comparing Gravimetric and Real-Time Sampling of PM2.5 Concentrations Inside Truck Cabins

    PubMed Central

    Zhu, Ying; Smith, Thomas J.; Davis, Mary E.; Levy, Jonathan I.; Herrick, Robert; Jiang, Hongyu

    2012-01-01

    As part of a study on truck drivers’ exposure and health risk, pickup and delivery (P&D) truck drivers’ on-road exposure patterns to PM2.5 were assessed in five weeklong sampling trips in metropolitan areas of five U.S. cities from April to August of 2006. Drivers were sampled with real-time (DustTrak) and gravimetric samplers to measure average in-cabin PM2.5 concentrations and to compare their correspondence in moving trucks. In addition, GPS measurements of truck locations, meteorological data, and driver behavioral data were collected throughout the day to determine which factors influence the relationship between real-time and gravimetric samplers. Results indicate that the association between average real-time and gravimetric PM2.5 measurements on moving trucks was fairly consistent (Spearman rank correlation of 0.63), with DustTrak measurements exceeding gravimetric measurements by approximately a factor of 2. This ratio differed significantly only between the industrial Midwest cities and the other three sampled cities scattered in the South and West. There was also limited evidence of an effect of truck age. Filter samples collected concurrently with DustTrak measurements can be used to calibrate average mass concentration responses for the DustTrak, allowing for real-time measurements to be integrated into longer-term studies of inter-city and intra-urban exposure patterns for truck drivers. PMID:21991940

  6. Comparing gravimetric and real-time sampling of PM(2.5) concentrations inside truck cabins.

    PubMed

    Zhu, Ying; Smith, Thomas J; Davis, Mary E; Levy, Jonathan I; Herrick, Robert; Jiang, Hongyu

    2011-11-01

    As part of a study on truck drivers' exposure and health risk, pickup and delivery (P&D) truck drivers' on-road exposure patterns to PM(2.5) were assessed in five, weeklong sampling trips in metropolitan areas of five U.S. cities from April to August of 2006. Drivers were sampled with real-time (DustTrak) and gravimetric samplers to measure average in-cabin PM(2.5) concentrations and to compare their correspondence in moving trucks. In addition, GPS measurements of truck locations, meteorological data, and driver behavioral data were collected throughout the day to determine which factors influence the relationship between real-time and gravimetric samplers. Results indicate that the association between average real-time and gravimetric PM(2.5) measurements on moving trucks was fairly consistent (Spearman rank correlation of 0.63), with DustTrak measurements exceeding gravimetric measurements by approximately a factor of 2. This ratio differed significantly only between the industrial Midwest cities and the other three sampled cities scattered in the South and West. There was also limited evidence of an effect of truck age. Filter samples collected concurrently with DustTrak measurements can be used to calibrate average mass concentration responses for the DustTrak, allowing for real-time measurements to be integrated into longer-term studies of inter-city and intra-urban exposure patterns for truck drivers. PMID:21991940

  7. Determination of PM2.5 sources using time-resolved integrated source and receptor models.

    PubMed

    García, José H; Li, Wen-Whai; Cárdenas, Nidia; Arimoto, Richard; Walton, John; Trujillo, David

    2006-12-01

    Multivariate statistical techniques are applied to particulate matter (PM) and meteorological data to identify the sources responsible for evening PM spikes at Sunland Park, NM (USA). The statistical techniques applied are principal components analysis (PCA), redundancy analysis (RDA), and absolute principal components scores analysis (APCSA), and the data evaluated are 3-h average (6-9 p.m.) PM(2.5) mass and chemical composition and 1-h average PM(2.5) and PM(10) mass and environmental data collected in the winter of 2002. Although the interpretation of the data was complicated by the presence of sources which are likely changing in time (e.g. brick kilns), the multivariate analyses indicate that the evening high PM(2.5) is associated with burning-activities occurring to the south of Sunland Park, and these emissions are characterized by elevated Sb, Cl(-), and elemental carbon; approximately 68% of the PM(2.5) mass can be attributed to this source. The PM(10) evening peaks, on the other hand, are mainly caused by resuspended dust generated by vehicular movements south of the site and transported by the local terrain-induced drainage flow. PMID:16901530

  8. Asymmetric multifractal detrending moving average analysis in time series of PM2.5 concentration

    NASA Astrophysics Data System (ADS)

    Zhang, Chen; Ni, Zhiwei; Ni, Liping; Li, Jingming; Zhou, Longfei

    2016-09-01

    In this paper, we propose the asymmetric multifractal detrending moving average analysis (A-MFDMA) method to explore the asymmetric correlation in non-stationary time series. The proposed method is applied to explore the asymmetric correlation of PM2.5 daily average concentration with uptrends or downtrends in China. In addition, shuffling and phase randomization procedures are applied to detect the sources of multifractality. The results show that existences of asymmetric correlations, and the asymmetric correlations are multifractal. Further, the multifractal scaling behavior in the Chinese PM2.5 is caused not only by long-range correlation but also by fat-tailed distribution, but the major source of multifractality is fat-tailed distribution.

  9. Integrated and real-time diffusion denuder sample for PM 2.5

    NASA Astrophysics Data System (ADS)

    Eatough, Delbert J.; Obeidi, Fida; Pang, Yanbo; Ding, Yiming; Eatough, Norman L.; Wilson, William E.

    Particulate matter (PM) is a complex mixture of stable condensed phases, adsorbed or dissolved gases, and semi-volatile materials, i.e. compounds that transfer between the gas and condensed phases. Fine particles in both rural and urban environments contain substantial quantities of semi-volatile material that can be lost from the particles during sample collection on a filter and during subsequent handling, storage and conditioning (or equilibration). These include ammonium nitrate, semi-volatile organic compounds and particle bound water. In addition, gas phase organic compounds can also be absorbed by a quartz filter. As a result, the concentrations of these species are often significantly in error for results obtained with a conventional single filter sampler. The accurate measurement of the mass and chemical components of fine particles will become more important as a result of the recent promulgation of fine particle standards by the US Environmental Protection Agency and the additional monitoring that will be required for implementation of those standards as well as for additional research on the sources and effects of PM. Past organic compound diffusion denuder samplers developed by us (BOSS, BYU Organic Sampling System) are not amenable to routine field use because of the need to independently determine the gas phase semi-volatile organic material breakthrough of the denuder for each sample. This problem has been eliminated in the Particle Concentrator-Brigham Young University Organic Sampling System (PC-BOSS) using a combined virtual impactor, particle-concentrator inlet to provide a concentrated stream of 0.1-2.5 μm particles. This is followed by a BOSS diffusion denuder and filter packs containing particle collecting and sorbent filters to collect particles, including any semi-volatile organic material or ammonium nitrate lost from the particles during sampling. The PC-BOSS contains a sequential sampler to allow for the routine collection of several

  10. Real-time particle monitor calibration factors and PM2.5 emission factors for multiple indoor sources.

    PubMed

    Dacunto, Philip J; Cheng, Kai-Chung; Acevedo-Bolton, Viviana; Jiang, Ruo-Ting; Klepeis, Neil E; Repace, James L; Ott, Wayne R; Hildemann, Lynn M

    2013-08-01

    Indoor sources can greatly contribute to personal exposure to particulate matter less than 2.5 μm in diameter (PM2.5). To accurately assess PM2.5 mass emission factors and concentrations, real-time particle monitors must be calibrated for individual sources. Sixty-six experiments were conducted with a common, real-time laser photometer (TSI SidePak™ Model AM510 Personal Aerosol Monitor) and a filter-based PM2.5 gravimetric sampler to quantify the monitor calibration factors (CFs), and to estimate emission factors for common indoor sources including cigarettes, incense, cooking, candles, and fireplaces. Calibration factors for these indoor sources were all significantly less than the factory-set CF of 1.0, ranging from 0.32 (cigarette smoke) to 0.70 (hamburger). Stick incense had a CF of 0.35, while fireplace emissions ranged from 0.44-0.47. Cooking source CFs ranged from 0.41 (fried bacon) to 0.65-0.70 (fried pork chops, salmon, and hamburger). The CFs of combined sources (e.g., cooking and cigarette emissions mixed) were linear combinations of the CFs of the component sources. The highest PM2.5 emission factors per time period were from burned foods and fireplaces (15-16 mg min(-1)), and the lowest from cooking foods such as pizza and ground beef (0.1-0.2 mg min(-1)). PMID:23784066

  11. Refined Assessment of Human PM2.5 Exposure in Chinese city by Incorporating Time-activity Data

    NASA Astrophysics Data System (ADS)

    Zhu, W.; Wang, H.

    2015-12-01

    Since urban residents tend to spend a majority of time indoors throughout a day, it has been widely discussed in recent years, whether fixed-site monitoring PM2.5 ambient concentration is feasible as a surrogate of human PM2.5 exposure. Comprehensive understanding of residents' daily time-activity patterns (TAP) and possible indoor behavior are urgently needed to perform a more accurate estimate of human PM2.5exposure, especially in China, where is experiencing rapid urbanization.Field surveys of TAP were carried out in a Chinese city of Suzhou from 2014 to 2015 to evaluate PM2.5 exposure in various micro-environments (ME, e.g., residence, outdoors and in-transit). We gathered and analyzed urban residents' seasonal time-activity data using 24h retrospective time-location diaries, as well as diversified exposure-related indoor information (e.g. ventilation, environment tobacco smoke and cooking). PM2.5exposure is calculated through the incorporation of ambient concentration data, modified indoor/outdoor empirical functions and TAP. The spatial distributions of TAP-based exposure and static-population based exposure are also compared.Residents in Suzhou urban area spend over 65% of time at home and 90% indoors. There are significant temporal (season, day type) and socioeconomic differences (gender, age, education, living alone, having children at home, employment status, etc.) of time-activity distributions, which makes the sum of PM2.5 ME exposure differs notably from static-population based ambient exposure. People prefer to spend more time at home both in winter (P<0.05) and on weekends (P<0.001), less time outdoors in winter but more on weekends (P<0.001). Gender, education and living alone are negative associated with time spent home, while age, children at home and employment status are positively related. On the other hand, due to lack of monitoring stations in unban Suzhou, the inverse distance squared weighting method is not ideally performed and may be less

  12. Using a Continuous Time Lag to Determine the Associations Between Ambient PM2.5 Hourly Levels and Daily Mortality

    PubMed Central

    Staniswalis, Joan G.; Yang, Hongling; Li, Wen-Whai; Kelly, Kerry E.

    2009-01-01

    We are interested in understanding the possible association between exposure to short-term PM2.5 peaks that have changing physical characteristics throughout the day and observable health outcomes (daily mortality). To this end, modern statistical methods are used here that allow for a continuous time lag between hourly PM2.5 mass concentration and daily mortality. The functional linear regression model was used to study how hourly PM2.5 mass of past days continuously influence the daily mortality count of the current day. Using a Poisson likelihood with the canonical link, we found that a 10 μg/m3 increase in the hourly PM2.5 above the hourly average is associated with 1.7% (.1, 3.4), 2.4% (1.2, 3.7), 1.6% (.6, 2.7), .8% (−.2, 1.8) higher risk of mortality on the same day, next day, 2-days and 3-days later, respectively. The increase in relative risk is statistically significant for lags of 0−2 days, but not at lag 3. The highest association between PM2.5 mass concentration and daily mortality was found to occur in the morning when both mass and PM number concentrations peak at roughly 8 a.m. (lag of 15, 39, and 63 hours). This morning time interval corresponds to automobile traffic rush-hour that coincides with a morning atmospheric inversion that traps high concentrations of nanoparticles. PMID:19842325

  13. Source Identification of PM2.5 in Steubenville, Ohio Using a Hybrid Method for Highly Time-resolved Data

    EPA Science Inventory

    A new source-type identification method, Reduction and Species Clustering Using Episodes (ReSCUE), was developed to exploit the temporal synchronicity between species to form clusters of species that vary together. High time-resolution (30 min) PM2.5 sampling was condu...

  14. Insights into the chemical characterization and sources of PM(2.5) in Beijing at a 1-h time resolution.

    PubMed

    Gao, Jian; Peng, Xing; Chen, Gang; Xu, Jiao; Shi, Guo-Liang; Zhang, Yue-Chong; Feng, Yin-Chang

    2016-01-15

    As the widespread application of online instruments penetrates the environmental fields, it is interesting to investigate the sources of fine particulate matter (PM2.5) based on the data monitored by online instruments. In this study, online analyzers with 1-h time resolution were employed to observe PM2.5 composition data, including carbon components, inorganic ions, heavy metals and gas pollutants, during a summer in Beijing. Chemical characteristics, temporal patterns and sources of PM2.5 are discussed. On the basis of hourly data, the mean concentration value of PM2.5 was 62.16±39.37 μg m(-3) (ranging from 6.69 to 183.67 μg m(-3)). The average concentrations of NO3(-), SO4(2-), NH4(+), OC and EC, the major chemical species, were 15.18±13.12, 14.80±14.53, 8.90±9.51, 9.32±4.16 and 3.08±1.43 μg m(-3), respectively. The concentration of PM2.5 varied during the online-sampling period, initially increasing and then subsequently decreasing. Three factor analysis models, including principal component analysis (PCA), positive matrix factorization (PMF) and Multilinear Engine 2 (ME2), were applied to apportion the PM2.5 sources. Source apportionment results obtained by the three different models were in agreement. Four sources were identified in Beijing during the sampling campaign, including secondary sources (38-39%), crustal dust (17-22%), vehicle exhaust (25-28%) and coal combustion (15-16%). Similar source profiles and contributions of PM2.5 were derived from ME2 and PMF, indicating the results of the two models are reasonable. The finding provides information that could be exploited for regular air control strategies. PMID:26519577

  15. Using a continuous time lag to determine the associations between ambient PM2.5 hourly levels and daily mortality.

    PubMed

    Staniswalis, Joan G; Yang, Hongling; Li, Wen-Whai; Kelly, Kerry E

    2009-10-01

    The authors are interested in understanding the possible association between exposure to short-term fine particulate matter (PM2.5) peaks that have changing physical characteristics throughout the day and observable health outcomes (daily mortality). To this end, modern statistical methods are used here that allow for a continuous time lag between hourly PM2.5 mass concentration and daily mortality. The functional linear regression model was used to study how hourly PM2.5 mass of past days continuously influences the daily mortality count of the current day. Using a Poisson likelihood with the canonical link, the authors found that a 10-microg/m3 increase in the hourly PM2.5 above the hourly average is associated with 1.7% (0.1, 3.4), 2.4% (1.2, 3.7), 1.6% (0.6, 2.7), and 0.8% (-0.2, 1.8) higher risk of mortality on the same day, next day, 2 days, and 3 days later, respectively. The increase in relative risk is statistically significant for lags of 0-2 days, but not at lag 3. The highest association between PM2.5 mass concentration and daily mortality was found to occur in the morning when both mass and PM number concentrations peak at approximately 8:00 a.m. (lag of 15, 39, and 63 hr). This morning time interval corresponds to automobile traffic rush hour that coincides with a morning atmospheric inversion that traps high concentrations of nanoparticles. PMID:19842325

  16. Measurement, time series analysis and source apportionment of inorganic and organic speciated PM(2.5) air pollution in Denver

    NASA Astrophysics Data System (ADS)

    Dutton, Steven James

    Particulate air pollution has demonstrated significant health effects ranging from worsening of asthma to increased rates of respiratory and cardiopulmonary mortality. These results have prompted the US-EPA to include particulate matter (PM) as one of the six criteria air pollutants regulated under the Clean Air Act. The diverse chemical make-up and physical characteristics of PM make it a challenging pollutant to characterize and regulate. Particulate matter less than 2.5 microns in diameter (PM2.5) has the ability to travel deep into the lungs and therefore has been linked with some of the more significant health effects. The toxicity of any given particle is likely dependent on its chemical composition. The goal of this project has been to chemically characterize a long time series of PM 2.5 measurements collected at a receptor site in Denver to a level of detail that has not been done before on this size data set. This has involved characterization of inorganic ions using ion chromatography, total elemental and organic carbon using thermal optical transmission, and organic molecular marker species using gas chromatography-mass spectrometry. Methods have been developed to allow for daily measurement and speciation for these compounds over a six year period. Measurement methods, novel approaches to uncertainty estimation, time series analysis, spectral and pattern analyses and source apportionment using two multivariate factor analysis models are presented. Analysis results reveal several natural and anthropogenic sources contributing to PM2.5 in Denver. The most distinguishable sources are motor vehicles and biomass combustion. This information will be used in a health effect analysis as part of a larger study called the Denver Aerosol Sources and Health (DASH) study. Such results will inform regulatory decisions and may help create a better understanding of the underlying mechanisms for the observed adverse health effects associated with PM2.5.

  17. Source identification of PM2.5 in Steubenville, Ohio using a hybrid method for highly time-resolved data.

    PubMed

    Vedantham, Ram; Landis, Matthew S; Olson, David; Pancras, Joseph Patrick

    2014-01-01

    A new source-type identification method, Reduction and Species Clustering Using Episodes (ReSCUE), was developed to exploit the temporal synchronicity typically observed between ambient species in high time resolution fine particulate matter (PM2.5) data to form clusters that vary together. High time-resolution (30 min) PM2.5 sampling was conducted for a month during the summer of 2006 in Steubenville, OH, an EPA designated nonattainment area for the U.S. National Ambient Air Quality Standards (NAAQS). When the data were evaluated, the species clusters from ReSCUE matched extremely well with the source types identified by EPA Unmix demonstrating that ReSCUE is a valuable tool in identifying source types. Results from EPA Unmix show that contributions to PM2.5 are mostly from iron/steel manufacturing (36% ± 9%), crustal matter (33% ± 11%), and coal combustion (11% ± 19%). More importantly, ReSCUE was useful in (i) providing objective data driven guidance for the number of source factors and key fitting species for EPA Unmix, and (ii) detecting tenuous associations between some species and source types in the results derived by EPA Unmix. PMID:24387270

  18. The association between greater continuity of care and timely measles-mumps-rubella vaccination.

    PubMed Central

    Christakis, D A; Mell, L; Wright, J A; Davis, R; Connell, F A

    2000-01-01

    OBJECTIVES: This study assessed whether greater continuity of care is associated with timely administration of measles-mumps-rubella (MMR) vaccination. METHODS: We studied 11,233 patients continuously enrolled in Group Health Cooperative (GHC) from birth to 15 months. We used a preestablished index to quantify continuity of care based on the number of primary care providers in relation to the number of clinic visits. MMR vaccination status at 15 months was assessed with automated immunization data systems at GHC. RESULTS: In a logistic regression model, both medium continuity (odds ratio [OR] = 1.20, 95% confidence interval [CI] = 1.08, 1.33) and high continuity (OR = 1.36, 95% CI = 1.22, 1.52) were associated with increased likelihood of being immunized by 15 months compared with patients in the lowest tercile of continuity of care. CONCLUSION: Greater continuity of care is associated with more timely immunization. PMID:10846516

  19. Real-time measurements of levoglucosan in fine aerosols (PM2.5) in the region of Paris (France)

    NASA Astrophysics Data System (ADS)

    Sciare, J.; Bonnaire, N.; Mocnik, G.; Bressi, M.; Petit, J.; Nicolas, J.; Sarda-Estève, R.

    2011-12-01

    Levoglucosan - one of the major saccharidic compounds produced by the combustion of cellulose and hemicellulose - is emitted in large amounts by wildfires or residential wood burning (during winter months). Over the past few years, this organic tracer has received more and more attention as it can be used in a quantitative way to derive atmospheric concentrations of biomass burning aerosols [Favez et al., 2010] which aerosol source has strong implications for climate and air quality studies. A new technique has been developed and is presented here to investigate real-time concentrations of levoglucosan in fine aerosols (PM2.5). This technique is based on a Particle-into-liquid-sampler (PILS, Brechtel Manufacturing inc., model 4002) used "on-line" and coupled with an electrospray ionisation - tandem mass spectrometry (ESI-MS/MS, Applied Biosystem model QTRAP 3200). Air was drawn in the PILS at 15LPM and removed from particles larger than 2.5μm aerodynamic diameter (AD) using a very sharp cyclone. Water-soluble aerosols were collected in the PILS and sent in the 10μL loop of the ESI-MS/MS at a flowrate of 50μL/min. Flow injection analysis (FIA) was then performed every 2.5min for the quantification of levoglucosan using ion source specific fragments (ions m/z 113). An internal levoglucosan standard was injected every 10 samples (i.e. every 25min) in order to check the stability of the mass spectrometry calibration. Field blanks were performed using a total filter upstream of the PILS instrument and did not show any detectable amount of levoglucosan. A limit of quantification (LOQ) better than 1 ng/m3 was calculated here for levoglucosan in FIA mode. Based on these settings, unattended measurements of levoglucosan by PILS-ESI-MS/MS have been performed every 2.5 min in the region of Paris for a couple of weeks during the winter 2011 showing concentrations ranging from below 1ng/m3 to more than 500ng/m3. These measurements were compared to measurements of Black

  20. Real-time measurements of levoglucosan in fine aerosols (PM2.5) in the region of Paris (France)

    NASA Astrophysics Data System (ADS)

    Sciare, J.; Bonnaire, N.; Mocnik, G.; Nicolas, J.; Petit, J. E.; Bressi, M.; Sarda-Estève, R.; Drinovic, L.

    2012-04-01

    Levoglucosan - one the major monosaccharide anhydride compounds produced by the combustion of cellulose and hemicellulose - is emitted in large amounts by wildfires or residential wood burning (during winter months). Over the past few years, this specific tracer has received more and more attention at it can be used in a quantitative way to derive atmospheric concentrations of biomass burning aerosols [Favez et al., 2010] which aerosol source has strong implications for climate and air quality studies. A new technique has been developed and is presented here to investigate real-time concentrations of levoglucosan in fine aerosols (PM2.5). This technique is based on a Particle-into-liquid-sampler (PILS, Brechtel Manufacturing inc., model 4002) used "on-line" and coupled with an electrospray ionisation source - tandem mass spectrometry (ESI-MS/MS, AB SCIEX model 3200 QTRAP). Air was drawn in the PILS at 15LPM and removed from particles larger than 2.5μm aerodynamic diameter (AD) using a very sharp cyclone. Water-soluble aerosols were collected in the PILS and sent in the 10μl loop of the ESI-MS/MS at a flowrate of 50μl/min. Flow injection analysis (FIA) was then performed every 2.5min for the quantification of levoglucosan using a specific transition 161-113 m/z (negative mode), by Multiple Reaction Monitoring (MRM) mode. An internal levoglucosan standard was injected every 10 samples (i.e. every 25min) in order to check the stability of the mass spectrometry calibration. Field blanks were performed using a total filter upstream of the PILS instrument and did not show any detectable amount of levoglucosan. A limit of quantification (LOQ) better than 1 ng/m3 was calculated here for levoglucosan in FIA mode. Based on these settings, unattended measurements of levoglucosan by PILS-ESI-MS/MS have been performed every 2.5 min in the region of Paris for a couple of weeks during the winter 2011 showing concentrations ranging from below 1ng/m3 to more than 500ng/m3. These

  1. Investigation of the time evolved spatial distribution of urban PM2.5 concentrations and aerosol composition during episodic high PM events in Yuma, AZ

    NASA Astrophysics Data System (ADS)

    Holmes, Heather A.; Pardyjak, Eric R.; Tyler, Bonnie J.; Peterson, Richard E.

    An interdisciplinary field study designed to investigate the spatial and temporal variability of atmospheric aerosols during high particulate matter ( PM) events along the US-Mexico border near Yuma, AZ was run during the week of March 18, 2007. The experiments were designed to quantify chemical composition and physical phenomena governing the transport of aerosols generated from episodic high PM events. The field study included two micrometeorological monitoring sites; one rural and one urban, equipped with sonic anemometers, continuous particulate concentration monitors and ambient aerosol collection equipment. In addition to the two main monitoring sites, five additional locations were equipped with optical particle counters to allow for the investigation of the spatial and temporal distribution of PM2.5 in the urban environment. In this paper, the meteorological and turbulence parameters governing the distribution and concentration of PM2.5 in the urban environment for two high-wind erosion events and one burning event are compared. The interaction between local atmospheric conditions and the particulate distribution is investigated. Results indicate that a single point measurement in the urban area of Yuma may not be sufficient for determining the ambient PM concentrations that the local population experiences; all three high PM events indicated PM2.5 varied considerably with maximum urban concentrations 5-10 times greater than the measured minima. A comparison of inorganic and carbonaceous content of the aerosols for the three high PM events is presented. The comparison shows an increase in silicon during crustal dust events and an increase in elemental and organic carbon during the burn event. Additional surface chemistry analysis, using time-of-flight secondary ion mass spectrometry (ToF-SIMS), for aerosols collected at the urban and rural sites during the burn event are discussed. The surface chemistry analysis provides positive ion mass spectra of organic

  2. Trend analysis of long-term temperature time series in the Greater Toronto Area (GTA)

    NASA Astrophysics Data System (ADS)

    Mohsin, Tanzina; Gough, William A.

    2010-08-01

    As the majority of the world’s population is living in urban environments, there is growing interest in studying local urban climates. In this paper, for the first time, the long-term trends (31-162 years) of temperature change have been analyzed for the Greater Toronto Area (GTA). Annual and seasonal time series for a number of urban, suburban, and rural weather stations are considered. Non-parametric statistical techniques such as Mann-Kendall test and Theil-Sen slope estimation are used primarily for the assessing of the significance and detection of trends, and the sequential Mann test is used to detect any abrupt climate change. Statistically significant trends for annual mean and minimum temperatures are detected for almost all stations in the GTA. Winter is found to be the most coherent season contributing substantially to the increase in annual minimum temperature. The analyses of the abrupt changes in temperature suggest that the beginning of the increasing trend in Toronto started after the 1920s and then continued to increase to the 1960s. For all stations, there is a significant increase of annual and seasonal (particularly winter) temperatures after the 1980s. In terms of the linkage between urbanization and spatiotemporal thermal patterns, significant linear trends in annual mean and minimum temperature are detected for the period of 1878-1978 for the urban station, Toronto, while for the rural counterparts, the trends are not significant. Also, for all stations in the GTA that are situated in all directions except south of Toronto, substantial temperature change is detected for the periods of 1970-2000 and 1989-2000. It is concluded that the urbanization in the GTA has significantly contributed to the increase of the annual mean temperatures during the past three decades. In addition to urbanization, the influence of local climate, topography, and larger scale warming are incorporated in the analysis of the trends.

  3. Decreased reaction time variability is associated with greater cardiovascular responses to acute stress.

    PubMed

    Wawrzyniak, Andrew J; Hamer, Mark; Steptoe, Andrew; Endrighi, Romano

    2016-05-01

    Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75-min recovery. RT measures were generated from an ex-Gaussian distribution that yielded three predictors: mu-RT, sigma-RT, and tau-RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = -.009, SE = .005, p = .09) and diastolic (B = -.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = -.007, SE = .003, p = .03) and impaired vagal tone (B = -.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses. PMID:26894967

  4. Decreased reaction time variability is associated with greater cardiovascular responses to acute stress

    PubMed Central

    Hamer, Mark; Steptoe, Andrew; Endrighi, Romano

    2016-01-01

    Abstract Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75‐min recovery. RT measures were generated from an ex‐Gaussian distribution that yielded three predictors: mu‐RT, sigma‐RT, and tau‐RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = −.009, SE = .005, p = .09) and diastolic (B = −.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = −.007, SE = .003, p = .03) and impaired vagal tone (B = −.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses. PMID:26894967

  5. Real-time bias-adjusted O 3 and PM 2.5 air quality index forecasts and their performance evaluations over the continental United States

    NASA Astrophysics Data System (ADS)

    Kang, Daiwen; Mathur, Rohit; Trivikrama Rao, S.

    2010-06-01

    The National Air Quality Forecast Capacity (NAQFC) system, which links NOAA's North American Mesoscale (NAM) meteorological model with EPA's Community Multiscale Air Quality (CMAQ) model, provided operational ozone (O 3) and experimental fine particular matter (PM 2.5) forecasts over the continental United States (CONUS) during 2008. This paper describes the implementation of a real-time Kalman Filter (KF) bias-adjustment technique to improve the accuracy of O 3 and PM 2.5 forecasts at discrete monitoring locations. The operational surface-level O 3 and PM 2.5 forecasts from the NAQFC system were post-processed by the KF bias-adjusted technique using near real-time hourly O 3 and PM 2.5 observations obtained from EPA's AIRNow measurement network. The KF bias-adjusted forecasts were created daily, providing 24-h hourly bias-adjusted forecasts for O 3 and PM 2.5 at all AIRNow monitoring sites within the CONUS domain. The bias-adjustment post-processing implemented in this study requires minimal computational cost; requiring less than 10 min of CPU on a single processor Linux machine to generate 24-h hourly bias-adjusted forecasts over the entire CONUS domain. The results show that the real-time KF bias-adjusted forecasts for both O 3 and PM 2.5 have performed as well as or even better than the previous studies when the same technique was applied to the historical O 3 and PM 2.5 time series from archived AQF in earlier years. Compared to the raw forecasts, the KF forecasts displayed significant improvement in the daily maximum 8-h O 3 and daily mean PM 2.5 forecasts in terms of both discrete (i.e., reduced errors, increased correlation coefficients, and index of agreement) and categorical (increased hit rate and decreased false alarm ratio) evaluation metrics at almost all locations during the study period in 2008.

  6. Characteristics and sensitivity analysis of multiple-time-resolved source patterns of PM2.5 with real time data using Multilinear Engine 2

    NASA Astrophysics Data System (ADS)

    Peng, Xing; Shi, Guo-Liang; Gao, Jian; Liu, Jia-Yuan; HuangFu, Yan-Qi; Ma, Tong; Wang, Hai-Ting; Zhang, Yue-Chong; Wang, Han; Li, Hui; Ivey, Cesunica E.; Feng, Yin-Chang

    2016-08-01

    With real time resolved data of Particulate matter (PM) and chemical species, understanding the source patterns and chemical characteristics is critical to establish controlling of PM. In this work, PM2.5 and chemical species were measured by corresponding online instruments with 1-h time resolution in Beijing. Multilinear Engine 2 (ME2) model was applied to explore the sources, and four sources (vehicle emission, crustal dust, secondary formation and coal combustion) were identified. To investigate the sensitivity of time resolution on the source contributions and chemical characteristics, ME2 was conducted with four time resolution runs (1-h, 2-h, 4-h, and 8-h). Crustal dust and coal combustion display large variation in the four time resolutions runs, with their contributions ranging from 6.7 to 10.4 μg m-3 and from 6.4 to 12.2 μg m-3, respectively. The contributions of vehicle emission and secondary formation range from 7.5 to 10.5 and from 14.7 to 16.7 μg m-3, respectively. The sensitivity analyses were conducted by principal component analysis-plot (PCA-plot), coefficient of divergence (CD), average absolute error (AAE) and correlation coefficients. For the four time resolution runs, the source contributions and profiles of crustal dust and coal combustion were more unstable than other source categories, possibly due to the lack of key markers of crustal dust and coal combustion (e.g. Si, Al). On the other hand, vehicle emission and crustal dust were more sensitive to time series of source contributions at different time resolutions. Findings in this study can improve our knowledge of source contributions and chemical characteristics at different time solutions.

  7. Do ewes born with a male co-twin have greater longevity with lambing over time?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Based on a recent analysis of historical records, ewes born co-twin to a ram had greater lifetime reproductive performance than ewes born co-twin to a ewe. We are interested in determining what component(s) of lifetime reproductive performance may be associated with a ewe’s co-twin sex. As an initi...

  8. DEVELOPMENT AND EVALUATION OF TIME- AND HEALTH-RELEVANT MONITORING METHODS FOR PM 2.5 EPISODE PREDICTION (SALT LAKE CITY EMPACT PROJECT)

    EPA Science Inventory

    Scope: Primary project goals are: (a) evaluate usefulness of a newly-developed, real-time, continuous monitor for total (nonvolatile plus semivolatile) PM2.5 mass, and particularly time- and health-relevance of this method as compared to other measurements of PM paramete...

  9. Increasing Time and Enriching Learning for Greater Equity in Schools: Perspective from Two Community Funders

    ERIC Educational Resources Information Center

    Lopez, Janet; Rivera, Peter

    2015-01-01

    Foundations across the country engage in grantmaking to eliminate the opportunity and achievement gaps in K-12 public schools. Many of the strategies and investments that funders have supported in recent years focus not only on "more time" but also on "better use of time" in schools. This better use of time centers on outcomes…

  10. Web-Based Time Entry Systems: Providing Greater Automation and Compliance

    ERIC Educational Resources Information Center

    Williams, Tracy

    2005-01-01

    Time and resources are becoming increasingly scarce in most higher education institutions today. As a result, colleges and universities are looking to streamline and simplify many costly, labor-intensive administrative processes. In this article, Tracy Williams examines how Web-based time-entry systems can help institutions save valuable time and…

  11. FIELD EVALUATION OF A MODIFIED DATARAM MIE SCATTERING MONITOR FOR REAL-TIME PM2.5 MASS CONCENTRATION MEASUREMENTS. (R827352C005)

    EPA Science Inventory

    In this paper, we investigated the feasibility of using a modified DataRAM nephelometer (RAM-1, MIE Inc., Billerica, MA) as a continuous PM2.5 monitor to measure concentrations of ambient and concentrated aerosols in real time. The DataRAM operated with a diffusion ...

  12. Source identification of ambient PM 2.5 for inhalation exposure studies in Steubenville, Ohio using highly time-resolved measurements

    NASA Astrophysics Data System (ADS)

    Morishita, Masako; Keeler, Gerald J.; Kamal, Ali S.; Wagner, James G.; Harkema, Jack R.; Rohr, Annette C.

    2011-12-01

    Recent epidemiological and toxicological studies have suggested that short-term elevations of ambient fine particle mass concentrations (aerodynamic diameter <2.5 μm, PM 2.5) can increase cardiac and pulmonary health risks. Thus, examining temporal variations of chemical changes in ambient PM 2.5 that could pose the greatest health risks and identifying its sources is critical so that the most toxic categories can be controlled. In this study we collected detailed air quality data in Steubenville, Ohio in August 2006 with the ultimate goal to evaluate associations between cardiovascular (CV) parameters measured in exposed laboratory animals and the chemical and elemental composition of PM 2.5. Current approaches using radiotelemetry to measure CV parameters in conscious laboratory animals are capable of collecting continuous recordings. To provide a robust and analogous dataset that can be better matched with CV responses, we have incorporated a highly time-resolved sampling method to characterize trace elements and thereby obtain more robust input data to determine potential emission sources. We applied positive matrix factorization (PMF) to trace element concentrations from 30-minute ambient PM 2.5 samples in Steubenville, Ohio, an area designated as a non-attainment area for the PM 2.5 National Ambient Air Quality Standards by the Environmental Protection Agency. The average ambient PM 2.5 filter-based mass concentration during the 8-hour summer exposure study period was 26 ± 11 μg m -3. Results from PMF indicated that six major factors contributed to the ambient PM 2.5 mass during this time: coal combustion/secondary (39 ± 46%), mobile sources (12 ± 14%), metal coating/processing (10 ± 11%), iron and steel manufacturing (5 ± 5%), Pb factor (5 ± 8%), and incineration/smelting (1 ± 3%). The objectives of this paper are (1) to present chemical composition of ambient PM 2.5 and its potential emission sources in Steubenville; and (2) to evaluate the PMF

  13. Evaluation of real-time PM2.5 forecasts and process analysis for PM2.5 formation over the eastern United States using the Eta-CMAQ forecast model during the 2004 ICARTT study

    NASA Astrophysics Data System (ADS)

    Yu, Shaocai; Mathur, Rohit; Schere, Kenneth; Kang, Daiwen; Pleim, Jonathan; Young, Jeffrey; Tong, Daniel; Pouliot, George; McKeen, Stuart A.; Rao, S. T.

    2008-03-01

    The performance of the Eta-Community Multiscale Air Quality (CMAQ) modeling system in forecasting PM2.5 and chemical species is assessed over the eastern United States with the observations obtained by aircraft (NOAA P-3 and NASA DC-8) and four surface monitoring networks (AIRNOW, IMPROVE, CASTNet and STN) during the 2004 International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) study. The results of the statistical analysis at the AIRNOW sites show that the model was able to reproduce the day-to-day and spatial variations of observed PM2.5 and captured a majority (73%) of PM2.5 observations within a factor of 2, with normalized mean bias of -21%. The consistent underestimations in regional PM2.5 forecast at other networks (IMPROVE and STN) were mainly due to the underestimation of total carbonaceous aerosols at both urban and rural sites. The significant underestimation of the "other" category, which predominantly is composed of primary emitted trace elements in the current model configuration, is also one of the reasons leading to the underestimation of PM2.5 at rural sites. The systematic overestimations of SO42- both at the surface sites and aloft, in part, suggest too much SO2 cloud oxidation due to the overestimation of SO2 and H2O2 in the model. The underestimation of NH4+ at the rural sites and aloft may be attributed to the exclusion of some sources of NH3 in the emission inventory. The systematic underestimations of NO3- may result from the general overestimations of SO42-. Note that there are compensating errors among the underestimation of PM2.5 species (such as total carbonaceous aerosols) and overestimation of PM2.5 species (such as SO42-), leading to generally better performance of PM2.5 mass. The systematic underestimation of biogenic isoprene (by ˜30%) and terpene (by a factor of 4) suggests that their biogenic emissions may have been biased low, whereas the consistent overestimations of toluene by the model under

  14. Identification of ambient PM 2.5 sources and analysis of pollution episodes in Detroit, Michigan using highly time-resolved measurements

    NASA Astrophysics Data System (ADS)

    Morishita, Masako; Keeler, Gerald J.; Kamal, Ali S.; Wagner, James G.; Harkema, Jack R.; Rohr, Annette C.

    2011-03-01

    Recent studies have indicated that the chemical composition of ambient PM 2.5, or fine particulate matter (aerodynamic diameter <2.5 μm), may be closely associated with the health effects induced by PM. Thus, identification of the sources of these components of PM 2.5 is critical to understanding source-specific health risks posed by PM 2.5. However, ambient PM measurements are typically 24-h average concentrations, masking the temporal variability of individual sources. These daily samples can limit our understanding of the associations between sources and observed heath effect parameters. In the present study, highly time-resolved sampling methods were utilized to characterize trace element concentrations and to obtain information on potential emission sources impacting a site in urban Detroit where a complex mixture of local point and mobile sources, as well as regional sources, is observed. Positive matrix factorization (PMF) was applied to 117 8-h PM 2.5 filter samples from which six major factors were extracted including secondary aerosol, gasoline-powered vehicles, iron and steel manufacturing, diesel-powered vehicles, refining, and sludge incineration. In addition, PMF was applied to 268 30-min PM 2.5 samples where six major source factors were identified including secondary aerosol, gasoline- and diesel-powered vehicles, iron and steel manufacturing, refining, sludge incineration, and cement/lime production. Contributions of various emission source factors and peak concentrations for each factor were characterized using detailed meteorology and, factor directionality analysis. Although some variations were observed between the 8-h integrated filter samples and the 30-min SEAS samples, the results from the two datasets are generally consistent, suggesting that 46% and 43% of ambient PM, respectively, is derived from local sources. These findings have advanced our understanding of temporal PM source-receptor relationships in a complex urban air shed.

  15. A time-series analysis of mortality and air temperature in Greater Beirut.

    PubMed

    El-Zein, Abbas; Tewtel-Salem, Mylene; Nehme, Gebran

    2004-09-01

    The literature on the association between health and weather in the temperate to semi-arid cities of the Eastern Mediterranean is scarce. The quantification of the relationship between temperature and daily mortality can be useful for developing policy interventions such as heat-warning systems. A time-series analysis of total daily mortality and weather data for the city of Beirut was carried out. The study covered the period between 1997 and 1999. Poisson auto-regressive models were constructed, with mean daily temperature and mean daily humidity as explanatory variables. Delayed effects, up to 2 weeks, were accounted for. The regression models were used next to assess the effect of an average increase in temperature on yearly mortality. The association between temperature and mortality was found to be significant. A relatively high minimum-mortality temperature (TMM) of 27.5 degrees C was calculated. A 1 degrees C rise in temperature yielded a 12.3% increase (95% confidence interval: 5.7-19.4%) and 2.9% decrease (95% confidence interval: 2-3.7%) in mortality, above and below TMM, respectively. Lag temperature variables were found to be significant below TMM but not above it. Where the temperature change was less than 0.5 degrees C, annual above-TMM losses were offset by below-TMM gains, within a 95% confidence interval. TMM for Beirut fell within the range usually associated with warm climates. However, the mild below-TMM and steep above-TMM slopes were more typical of cities with temperate to cold climates. Our findings suggest that heat-related mortality at moderately high temperatures can be a significant public health issue in countries with warm climates. Moreover, at the projected climate change over the next 50 years, heat-related losses are unlikely to be offset by cold-related gains. PMID:15325159

  16. Air pollution and early deaths in the United States. Part II: Attribution of PM2.5 exposure to emissions species, time, location and sector

    NASA Astrophysics Data System (ADS)

    Dedoussi, Irene C.; Barrett, Steven R. H.

    2014-12-01

    Combustion emissions constitute the largest source of anthropogenic emissions in the US, and lead to the degradation of air quality and human health. In Part I we computed the population fine particulate matter (PM2.5) exposure and number of early deaths caused by emissions from six major sectors: electric power generation, industry, commercial and residential activities, road transportation, marine transportation and rail transportation. In Part II we attribute exposure and early deaths to sectors, emissions species, time of emission, and location of emission. We apply a long-term adjoint sensitivity analysis and calculate the four dimensional sensitivities (time and space) of PM2.5 exposure with respect to each emissions species. Epidemiological evidence is used to relate increased population exposure to premature mortalities. This is the first regional application of the adjoint sensitivity analysis method to characterize long-term air pollution exposure. (A global scale application has been undertaken related to intercontinental pollution.) We find that for the electric power generation sector 75% of the attributable PM2.5 exposure is due to SO2 emissions, and 80% of the annual impacts are attributed to emissions from April to September. In the road transportation sector, 29% of PM2.5 exposure is due to NOx emissions and 33% is from ammonia (NH3), which is a result of emissions after-treatment technologies. We estimate that the benefit of reducing NH3 emissions from road transportation is ∼20 times that of NOx per unit mass. 75% of the road transportation ammonia impacts occur during the months October to March. We publicly release the sensitivity matrices computed, noting their potential use as a rapid air quality policy assessment tool.

  17. A CROSS-PROVINCE ANALYSIS OF URBAN AND RURAL INDOOR PM2.5 EXPOSURE IN CHINA USING TIME USE SURVEY

    NASA Astrophysics Data System (ADS)

    Shimada, Yoko; Guo, Minna; Kurata, Gakuji; Matsuoka, Yuzuru

    In developing countries in Asia and other parts of the world, most energy sources used in the home are solid fuels such as coal and biomass (firewood, crop residue and animal dung). Particulate matter 2.5, consisting of particles with an aerodynamic diameter of 2.5 um or less, produced through combustion of these fuels inside the residence for cooking and heating has an adverse impact on people's health. We estimated PM2.5 exposure concentration in indoor microenvironment for each cohort of urban and rural area in ten provinces of China, using statistical data on time use survey and domestic energy consumption. The study found that, in each province, the exposure concentration in rural area was higher than in urban area, unemployed women between the ages of 60 and 64 had the highest estimate for exposure concentration at 3027 μg/m3. The study also found that the exposure concentration for individual cohorts in each province was greatly affected by people's use of time indoors, fuel consumption such as coal or biomass and floor space.

  18. Near real time monitoring of biomass burning particulate emissions (PM2.5) across contiguous United States using multiple satellite instruments

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoyang; Kondragunta, Shobha; Schmidt, Christopher; Kogan, Felix

    Biomass burning is a major source of aerosols that affect air quality and the Earth's radiation budget. Current estimates of biomass burning emissions vary markedly due to uncertainties in biomass density, combustion efficiency, emission factor, and burned area. This study explores the modeling of biomass burning emissions using satellite-derived vegetative fuel loading, fuel moisture, and burned area across Contiguous United States (CONUS). The fuel loading is developed from Moderate-Resolution Imaging Spectroradiometer (MODIS) data including land cover type, vegetation continuous field, and monthly leaf area index. The weekly fuel moisture category is retrieved from AVHRR (Advanced Very High Resolution Radiometer) Global Vegetation Index (GVIx) data for the determination of fuel combustion efficiency and emission factor. The burned area is simulated using half-hourly fire sizes obtained from the GOES (Geostationary Operational Environmental Satellites) Wildfire Automated Biomass Burning Algorithm (WF_ABBA) fire product. By integrating all these parameters, quantities of PM2.5 (particulate mass for particles with diameter <2.5 μm) aerosols are calculated for each individual fire at an interval of half hour from 2002-2005 across CONUS. The PM2.5 estimates indicate that the annual PM2.5 emissions are 3.49 × 10 5, 3.30 × 10 5, 1.80 × 10 5, and 2.24 × 10 5 tons for 2002 (April to December), 2003, 2004, and 2005, respectively. Among various ecosystems, forest fires release more than 44% of the emissions although the related burned areas only account for less than 30%. Spatially, PM2.5 emissions are larger in California for all these years, but only for some individual years in Oregon, Montana, Arkansas, Florida, Arizona, Louisiana, and Idaho. Finally, the calculated PM2.5 emissions are evaluated using national wildfire emission inventory data (NWEI) and compared with estimates from different fuel loadings. The difference between NWEI and GOES fire-based estimate

  19. Greater India

    NASA Astrophysics Data System (ADS)

    Ali, Jason R.; Aitchison, Jonathan C.

    2005-10-01

    "Greater India" is an 80-yr-old concept that has been used by geoscientists in plate tectonic models of the India-Asia collision system. Numerous authors working on the orogen and/or plate models of the broader region have added various sized chunks of continental lithosphere to the now northern edge of their reconstructed Indian plate. Prior to plate tectonic theory, Emile Argand (1924) [Argand, E., 1924. La tectonique de l' Asie. Proc. 13th Int. Geol. Cong. 7 (1924), 171-372.] and Arthur Holmes (1965) [Holmes, A., 1965. Principles of Physical Geology, Second Edition. The Ronald Press Company, New York, 1128.] thought that the Himalayan Mountains and Tibetan Plateau had been raised due to the northern edge of the Indian craton under-thrusting the entire region. Since the advent of plate tectonic theory, Greater India proposals have been based principally on three lines of logic. One group of workers has added various amounts of continental lithosphere to India as part of their Mesozoic Gondwana models. A second form of reconstruction is based on Himalayan crustal-shortening estimates. A third body of researchers has used India continent extensions as means of allowing initial contact between the block and the Eurasian backstop plate in southern Tibet to take place at various times between the Late Cretaceous and late Eocene in what we call "fill-the-gap" solutions. The Indian craton and the southern edge of Eurasia were almost invariably some distance from one another when the collision was supposed to have started; extensions to the sub-continent were used to circumvent the problem. Occasionally, Greater India extensions have been based on a combination of fill-the-gap and shortening estimate arguments. In this paper, we exhume and re-examine the key Greater India proposals. From our analysis, it is clear that many proponents have ignored key information regarding the sub-continent's pre break-up position within Gondwana and the bathymetry of the Indian Ocean

  20. Oman-India pipeline sets survey challenges. Crossing involves most rugged terrain, water depths four times greater than previous attempts

    SciTech Connect

    Flynn, J.

    1995-02-01

    Decisions concerning the route for the world`s deepest pipeline call for some of the most challenging commercial oceanographic and engineering surveys ever undertaken. Oman Oil Co.`s 1, 170-kilometer pipeline will carry 2 billion cubic feet of gas daily across the Arabian Sea from Oman to the northern coast of India at the Gulf of Kutch. Not only will the project be in water depths four times greater than any previous pipeline, but it will cross some of the world`s most rugged seabed terrain, traversing ridges and plunging into deep canyons. Project costs are likely to approach $5 billion.

  1. Time-Resolved Gas-Phase Kinetic, Quantum Chemical, and RRKM Studies of the Reaction of Silylene with 2,5-Dihydrofuran.

    PubMed

    Becerra, Rosa; Cannady, J Pat; Pfrang, Christian; Walsh, Robin

    2015-11-19

    Time-resolved kinetics studies of silylene, SiH2, generated by laser flash photolysis of phenylsilane, were performed to obtain rate coefficients for its bimolecular reaction with 2,5-dihydrofuran (2,5-DHF). The reaction was studied in the gas phase over the pressure range of 1-100 Torr in SF6 bath gas, at five temperatures in the range of 296-598 K. The reaction showed pressure dependences characteristic of a third body assisted association. The second-order rate coefficients obtained by Rice-Ramsperger-Kassel-Marcus (RRKM)-assisted extrapolation to the high-pressure limit at each temperature fitted the following Arrhenius equation where the error limits are single standard deviations: log(k/cm(3) molecule(-1) s(-1)) = (-9.96 ± 0.08) + (3.38 ± 0.62 kJ mol(-1))/RT ln 10. End-product analysis revealed no GC-identifiable product. Quantum chemical (ab initio) calculations indicate that reaction of SiH2 with 2,5-DHF can occur at both the double bond (to form a silirane) and the O atom (to form a donor-acceptor, zwitterionic complex) via barrierless processes. Further possible reaction steps were explored, of which the only viable one appears to be decomposition of the O-complex to give 1,3-butadiene + silanone, although isomerization of the silirane cannot be completely ruled out. The potential energy surface for SiH2 + 2,5-DHF is consistent with that of SiH2 with Me2O, and with that of SiH2 with cis-but-2-ene, the simplest reference reactions. RRKM calculations incorporating reaction at both π- and O atom sites, can be made to fit the experimental rate coefficient pressure dependence curves at 296-476 K, giving values for k(∞)(π) and k(∞)(O) that indicate the latter is larger in magnitude at all temperatures, in contrast to values from individual model reactions. This unexpected result suggests that, in 2,5-DHF with its two different reaction sites, the O atom exerts the more pronounced electrophilic attraction on the approaching silylene. Arrhenius parameters

  2. Estimation of diurnal and seasonal variations of primary and secondary organic carbon concentrations using highly time resolved PM2.5 measurements

    NASA Astrophysics Data System (ADS)

    Kim, W. V.; Lee, H.; Kim, J.

    2011-12-01

    Recently, several investigations have been carried out to identify secondary organic carbon (SOC) contributions to total organic carbon (TOC) mass concentrations. Since direct SOC measurements cannot be made due to limitations of current measurement techniques, alternatively, empirical models based on measured particulate matter (PM) and trace gas data are used to estimate SOC concentrations. In this study, the measurement took place in Seoul from January to December 2010. The amounts of carbonaceous and ionic species of PM2.5 (Particles less than 2.5 micrometers in diameter) were measured hourly with a Sunset Laboratory semi-continuous OC/elemental carbon (EC) analyzer and an Ion chromatography analyzer, respectively. The amounts of primary organic carbon (POC) and SOC were estimated using an EC tracer method and multiple regression analysis based on hourly PM2.5 data. Both methods, which use tracer species of POC and SOC formations, estimated that SOC concentrations account for about 20% of TOC concentrations. The SOC concentrations estimated by the multiple regression analysis are comparable to those derived from the EC tracer method with the small differences in magnitude. Seasonal variations of POC, TOC, and EC concentrations show peaks in autumn and winter whereas SOC concentrations are enhanced in summer and autumn. Diurnal variations of the estimated SOCs show peaks at around 15:00 local time (LT) while POC, TOC and EC concentrations show peaks at morning and midnight. In conclusion, temporal characteristics of POC, which account for large portion of TOC, show good agreement with those of TOC and EC. Both seasonal and diurnal characteristics of SOC concentrations, however, are unveiled to be different from those of POC and TOC. POC and TOC concentrations were directly affected by primary sources while SOC peaks were found in ozone rich conditions with enhanced atmospheric radiation.

  3. Air quality forecasting for winter-time PM2.5 episodes occurring in multiple cities in central and southern Chile

    NASA Astrophysics Data System (ADS)

    Saide, Pablo E.; Mena-Carrasco, Marcelo; Tolvett, Sebastian; Hernandez, Pablo; Carmichael, Gregory R.

    2016-01-01

    Episodic air quality degradation due to particles occurs in multiple cities in central and southern Chile during the austral winter reaching levels up to 300-800 µg/m3 hourly PM2.5, which can be associated with severe effects on human health. An air quality prediction system is developed to predict such events in near real time up to 3 days in advance for nine cities with regular air quality monitoring: Santiago, Rancagua, Curicó, Talca, Chillan, Los Ángeles, Temuco, Valdivia, and Osorno. The system uses the Weather Research and Forecasting with Chemistry model configured with a nested 2 km grid-spacing domain to predict weather and inert tracers. The tracers are converted to hourly PM2.5 concentrations using an observationally based calibration which is substantially less computationally intensive than a full chemistry model. The conversion takes into account processes occurring in these cities, including higher likelihood of episode occurrence during weekends and during colder days, the latter related to increased wood-burning-stove activity for heating. The system is calibrated and evaluated for April-August 2014 where it has an overall skill of 53-72% of episodes accurately forecasted (61-76% for the best initialization) which is better than persistence for most stations. Forecasts one, two, and three days in advance all have skill in forecasting events but often present large variability within them due to different meteorological initializations. The system is being implemented in Chile to assist authority decisions not only to warn the population but also to take contingency-based emission restrictions to try to avoid severe pollution events.

  4. PM2.5 Characterization for Time Series Studies: Organic Molecular Marker Speciation Methods and Observations from Daily Measurements in Denver

    PubMed Central

    Dutton, Steven J.; Williams, Daniel E.; Garcia, Jessica K.; Vedal, Sverre; Hannigan, Michael P.

    2009-01-01

    Particulate matter less than 2.5 microns in diameter (PM2.5) has been shown to have a wide range of adverse health effects and consequently is regulated in accordance with the US-EPA’s National Ambient Air Quality Standards. PM2.5 originates from multiple primary sources and is also formed through secondary processes in the atmosphere. It is plausible that some sources form PM2.5 that is more toxic than PM2.5 from other sources. Identifying the responsible sources could provide insight into the biological mechanisms causing the observed health effects and provide a more efficient approach to regulation. This is the goal of the Denver Aerosol Sources and Health (DASH) study, a multi-year PM2.5 source apportionment and health study. The first step in apportioning the PM2.5 to different sources is to determine the chemical make-up of the PM2.5. This paper presents the methodology used during the DASH study for organic speciation of PM2.5. Specifically, methods are covered for solvent extraction of non-polar and semi-polar organic molecular markers using gas chromatography-mass spectrometry (GC-MS). Vast reductions in detection limits were obtained through the use of a programmable temperature vaporization (PTV) inlet along with other method improvements. Results are presented for the first 1.5 years of the DASH study revealing seasonal and source-related patterns in the molecular markers and their long-term correlation structure. Preliminary analysis suggests that point sources are not a significant contributor to the organic molecular markers measured at our receptor site. Several motor vehicle emission markers help identify a gasoline/diesel split in the ambient data. Findings show both similarities and differences when compared with other cities where similar measurements and assessments have been made. PMID:20161318

  5. Wavefront curvature sensing in a 2.5m wide-field telescope: design, analysis, and implementation for real-time correction of telescope alignment

    NASA Astrophysics Data System (ADS)

    Lousberg, Gregory P.; Moreau, Vincent; Pirnay, Olivier; Gloesener, Pierre; Flebus, Carlo

    2015-09-01

    In the framework of the design and manufacturing of a wide-field 2.5m telescope for the Observatorio Astrofisica de Javalambre (OAJ), AMOS has developed a novel wavefront sensing system that allows for real time correction of the alignment of the telescope without perturbing the acquisition of science images. The system is based on the wavefront curvature sensing (WCS) technique in which two out-of-focus images of a star are used for reconstructing the telescope wavefront error. Any deviations from the nominal wavefront error that is obtained after telescope final alignment are tracked and corrective actions can be implemented so as to optimize the telescope optical quality. The wavefront reconstruction technique and the associated corrections of the telescope alignment have been modelled and analyzed so as to validate the proposed approach before implementation in the telescope. To this aim, a bespoke coupled Zemax-Matlab model has been developed by AMOS. The model incorporates the algorithm for the telescope wavefront error reconstruction from out-of-focus images and computation of the alignment corrections in the telescope model. The justification of the wavefront sensing approach, its robustness against several sources of errors, as well as the selection of the appropriate equipment for its implementation in the telescope are discussed on the basis of this combined model.

  6. Greater Melbourne.

    PubMed

    Wulff, M; Burke, T; Newton, P

    1986-03-01

    With more than a quarter of its population born overseas, Melbourne, Australia, is rapidly changing from an all-white British outpost to a multicultural, multilingual community. Since the "white" Australian policy was abandoned after World War II, 3 million immigrants from 100 different countries have moved to Australia. Most of the immigrants come from New Zealand, Rhodesia, South Africa, Britain, Ireland, Greece, Turkey, Yugoslavia, Poland, and Indochina. Melbourne is Australia's 2nd largest city and houses 1 out of 5 Australians. Its 1984 population was 2,888,400. Melbourne's housing pattern consists of subdivisions; 75% of the population live in detached houses. Between 1954 and 1961 Melbourne grew at an annual rate of 3.5%; its growth rate between 1961 and 1971 still averaged 2.5%. In the 1970s the growth rate slowed to 1.4%. Metropolitan Melbourne has no central government but is divided into 56 councils and 8 regions. Both Australia's and Melbourne's fertility rates are high compared to the rest of the developed world, partly because of their younger age structure. 41% of Melbourne's population was under age 24 in 1981. Single-person households are growing faster than any other type. 71% of the housing is owner-occupied; in 1981 the median sized dwelling had 5.2 rooms. Public housing only accounts for 2.6% of all dwellings. Fewer students graduate from high school in Australia than in other developed countries, and fewer graduates pursue higher education. Melbourne's suburban sprawl promotes private car travel. In 1980 Melbourne contained more than 28,000 retail establishments and 4200 restaurants and hotels. Industry accounts for 30% of employment, and services account for another 30%. Its largest industries are motor vehicles, clothing, and footware. Although unemployment reached 10% after the 1973 energy crisis, by 1985 it was down to 6%. PMID:12340610

  7. Comparative study using oral solutions of bambuterol once daily or terbutaline three times daily in 2-5-year-old children with asthma. Bambuterol Multicentre Study Group.

    PubMed

    Kuusela, A L; Marenk, M; Sandahl, G; Sanderud, J; Nikolajev, K; Persson, B

    2000-03-01

    The aim of this study was to compare safety and efficacy of bambuterol hydrochloride (10 mg) oral solution administered once daily in the evening with terbutaline sulphate (0.075 mg/kg body weight) oral solution administered three times daily in 2-5-year-old children with asthma. There were two treatment groups: (2/3) of the patients received bambuterol and (1/3) received terbutaline. The study was double-blind, randomized, and of a parallel group design, and it lasted for 3 months after a 2-week run-in period. The primary objective was to evaluate safety (adverse events, and changes in blood pressure, pulse rate, hematology, and clinical chemistry parameters). Plasma concentrations of terbutaline and/or bambuterol were also measured. Evaluation of efficacy (diary card data) was a secondary objective. A total of 155 patients (range, 2-6 years; 3 patients were 6 years old at randomization) were treated with the study drugs; 104 patients received bambuterol and 51 patients received terbutaline. Both treatments showed a good safety profile with respect to clinical and laboratory tests, and they were generally well tolerated. Reported adverse events were mild to moderate. There were no statistically significant differences between treatment groups in any of the efficacy variables (diary variables: peak expiratory flow (PEF), asthma symptoms, restlessness, other reported symptoms, use of inhaled bronchodilators, and nighttime awakenings). For morning PEF, the mean increase from run-in to treatment was 16.9 L/min in the terbutaline group and 23.3 L/min in the bambuterol group. For evening PEF, the mean increase was 20.2 L/min in the terbutaline group and 20.6 L/min in the bambuterol group. In conclusion, once-daily bambuterol is as safe and effective as terbutaline given three times daily. The study also confirmed that bambuterol has a 24-hr duration of action, and therefore its once daily administration, makes it a preferred bronchodilator agent. Pediatr Pulmonol. 2000

  8. INTERCOMPARISON OF NEAR REAL-TIME MONITORS OF PM2.5 NITRATE AND SULFATE AT THE U.S. ENVIRONMENTAL PROTECTION AGENCY ATLANTA SUPERSITE

    EPA Science Inventory

    Five new instruments for semi-continuous measurements of fine particle (PM2.5) nitrate and sulfate were deployed at the Atlanta Supersite Experiment during an intensive study in August 1999. The instruments measured bulk aerosol chemical composition at rates ranging from every...

  9. Greater-than-Class C low-level radioactive waste characterization. Appendix A-2: Timing of greater-than-Class C low-level radioactive waste from nuclear power plants

    SciTech Connect

    Steinke, W.F.

    1994-09-01

    Planning for the storage or disposal of greater-than-Class C low-level radioactive waste (GTCC LLW) requires characterization of that waste. Timing, or the date the waste will require storage or disposal, is an integral aspect of that planning. The majority of GTCC LLW is generated by nuclear power plants, and the length of time a reactor remains operational directly affects the amount of GTCC waste expected from that reactor. This report uses data from existing literature to develop high, base, and low case estimates for the number of plants expected to experience (a) early shutdown, (b) 40-year operation, or (c) life extension to 60-year operation. The discussion includes possible effects of advanced light water reactor technology on future GTCC LLW generation. However, the main focus of this study is timing for shutdown of current technology reactors that are under construction or operating.

  10. Identifying Optimal Temporal Scale for the Correlation of AOD and Ground Measurements of PM2.5 to Improve the Modeling Performance in a Real-Time Air Quality Estimation System

    NASA Technical Reports Server (NTRS)

    Li,Hui; Faruque, Fazlay; Williams, Worth; Al-Hamdan, Mohammad; Luvall, Jeffrey; Crosson, William; Rickman, Douglas; Limaye, Ashutosh

    2008-01-01

    Aerosol optical depth (AOD), derived from satellite measurements using Moderate Resolution Imaging Spectrometer (MODIS), offers indirect estimates of particle matter. Research shows a significant positive correlation between satellite-based measurements of AOD and ground-based measurements of particulate matter with aerodynamic diameter less than or equal to 2.5 micrometers (PM2.5). In addition, satellite observations have also shown great promise in improving estimates of PM2.5 air quality surface. Research shows that correlations between AOD and ground PM2.5 are affected by a combination of many factors such as inherent characteristics of satellite observations, terrain, cloud cover, height of the mixing layer, and weather conditions, and thus might vary widely in different regions, different seasons, and even different days in a same location. Analysis of correlating AOD with ground measured PM2.5 on a day-to-day basis suggests the temporal scale, a number of immediate latest days for a given run's day, for their correlations needs to be considered to improve air quality surface estimates, especially when satellite observations are used in a real-time pollution system. The second reason is that correlation coefficients between AOD and ground PM2.5 cannot be predetermined and needs to be calculated for each day's run for a real-time system because the coefficients can vary over space and time. Few studies have been conducted to explore the optimal way to apply AOD data to improve model accuracies of PM2.5 surface estimation in a real-time air quality system. This paper discusses the best temporal scale to calculate the correlation of AOD and ground particle matter data to improve the results of pollution models in real-time system.

  11. Testing Age-Paced Parenting Newsletters up to Age 3: Greater Impact on First-Time Parents

    ERIC Educational Resources Information Center

    Ostergren, Carol S.; Riley, David A.

    2012-01-01

    An age-paced newsletter for parents of toddlers was evaluated. Mothers reported the newsletters were as useful as information from doctors or nurses and more useful than other sources of information. We hypothesized and found that first-time mothers reported the newsletters more useful than experienced mothers--reading more of the newsletters and…

  12. Real-time earthquake alert system for the greater San Francisco Bay Area: a prototype design to address operational issues

    SciTech Connect

    Harben, P.E.; Jarpe, S.; Hunter, S.

    1996-12-10

    The purpose of the earthquake alert system (EAS) is to outrun the seismic energy released in a large earthquake using a geographically distributed network of strong motion sensors that telemeter data to a rapid CPU-processing station, which then issues an area-wide warning to a region before strong motion will occur. The warning times involved are short, from 0 to 30 seconds or so; consequently, most responses must be automated. The San Francisco Bay Area is particularly well suited for an EAS because (1) large earthquakes have relatively shallow hypocenters (10- to 20-kilometer depth), giving favorable ray-path geometries for larger warning times than deeper from earthquakes, and (2) the active faults are few in number and well characterized, which means far fewer geographically distributed strong motion sensors are (about 50 in this region). An EAS prototype is being implemented in the San Francisco Bay Area. The system consists of four distinct subsystems: (1) a distributed strong motion seismic network, (2) a central processing station, (3) a warning communications system and (4) user receiver and response systems. We have designed a simple, reliable, and inexpensive strong motion monitoring station that consists of a three-component Analog Devices ADXLO5 accelerometer sensing unit, a vertical component weak motion sensor for system testing, a 16-bit digitizer with multiplexing, and communication output ports for RS232 modem or radio telemetry. The unit is battery-powered and will be sited in fire stations. The prototype central computer analysis system consists of a PC dam-acquisition platform that pipes the incoming strong motion data via Ethernet to Unix-based workstations for dam processing. Simple real-time algorithms, particularly for magnitude estimation, are implemented to give estimates of the time since the earthquake`s onset its hypocenter location, its magnitude, and the reliability of the estimate. These parameters are calculated and transmitted

  13. Effect of Reflow Time on Wetting Behavior, Microstructure Evolution, and Joint Strength of Sn-2.5Ag-0.5Cu Solder on Bare and Nickel-Coated Copper Substrates

    NASA Astrophysics Data System (ADS)

    Sona, Mrunali; Prabhu, K. Narayan

    2016-04-01

    The effect of reflow time on wetting behavior of Sn-2.5Ag-0.5Cu lead-free solder on bare and nickel-coated copper substrates has been investigated. The solder alloy was reflowed at 270°C for various reflow times of 10 s, 100 s, 300 s, and 500 s. On bare copper substrate, the intermetallic compound (IMC) thickness increased with increase in reflow time, whereas on Ni-coated Cu substrate, the IMC thickness increased up to 300 s followed by a drop for solder alloy reflowed for 500 s. The spreading behavior of the solder alloy was categorized into capillary, gravity (diffusion), and viscous zones. Gravity zone was obtained from 3.8 ± 0.43 s to 38.97 ± 3.38 s and from 5.99 ± 0.5 s to 77.82 ± 8.84 s for the Sn-2.5Ag-0.5Cu/Cu and Sn-2.5Ag-0.5Cu/Ni/Cu system, respectively. Sn-2.5Ag-0.5Cu solder alloy was also reflowed for the period corresponding to the end of the gravity zone (40 s and 80 s on bare and Ni-coated Cu, respectively). The joint strength was maximum at reflow time of 40 s and 80 s for the Sn-2.5Ag-0.5Cu/Cu and Sn-2.5Ag-0.5Cu/Ni/Cu system, respectively. The dynamic contact angle at the end of the gravity (diffusion) zone (θ gz) was found to be a better parameter compared with the stabilized contact angle (θ f) to assess the effect of the wettability of the liquid solder on the microstructure and joint strength. The present investigation reveals the significance of the gravity zone in assessment of optimum reflow time for lead-free solder alloys.

  14. Effect of Reflow Time on Wetting Behavior, Microstructure Evolution, and Joint Strength of Sn-2.5Ag-0.5Cu Solder on Bare and Nickel-Coated Copper Substrates

    NASA Astrophysics Data System (ADS)

    Sona, Mrunali; Prabhu, K. Narayan

    2016-07-01

    The effect of reflow time on wetting behavior of Sn-2.5Ag-0.5Cu lead-free solder on bare and nickel-coated copper substrates has been investigated. The solder alloy was reflowed at 270°C for various reflow times of 10 s, 100 s, 300 s, and 500 s. On bare copper substrate, the intermetallic compound (IMC) thickness increased with increase in reflow time, whereas on Ni-coated Cu substrate, the IMC thickness increased up to 300 s followed by a drop for solder alloy reflowed for 500 s. The spreading behavior of the solder alloy was categorized into capillary, gravity (diffusion), and viscous zones. Gravity zone was obtained from 3.8 ± 0.43 s to 38.97 ± 3.38 s and from 5.99 ± 0.5 s to 77.82 ± 8.84 s for the Sn-2.5Ag-0.5Cu/Cu and Sn-2.5Ag-0.5Cu/Ni/Cu system, respectively. Sn-2.5Ag-0.5Cu solder alloy was also reflowed for the period corresponding to the end of the gravity zone (40 s and 80 s on bare and Ni-coated Cu, respectively). The joint strength was maximum at reflow time of 40 s and 80 s for the Sn-2.5Ag-0.5Cu/Cu and Sn-2.5Ag-0.5Cu/Ni/Cu system, respectively. The dynamic contact angle at the end of the gravity (diffusion) zone ( θ gz) was found to be a better parameter compared with the stabilized contact angle ( θ f) to assess the effect of the wettability of the liquid solder on the microstructure and joint strength. The present investigation reveals the significance of the gravity zone in assessment of optimum reflow time for lead-free solder alloys.

  15. A Commercial Real-Time PCR Kit Provides Greater Sensitivity than Direct Sequencing to Detect KRAS Mutations

    PubMed Central

    Angulo, Bárbara; García-García, Elena; Martínez, Rebeca; Suárez-Gauthier, Ana; Conde, Esther; Hidalgo, Manuel; López-Ríos, Fernando

    2010-01-01

    KRAS mutation testing has become a standard procedure in the management of patients with carcinomas. The most frequently used method for KRAS testing is direct sequencing of PCR products. The development of commercial real-time quantitative PCR kits offers a useful alternative since they are in theory much more sensitive than direct sequencing and they avoid post- PCR handling. We present our experience as a reference center for the study of KRAS mutations, comparing direct sequencing and the use of a commercial real-time quantitative PCR kit, as well as determining the sensitivity of both procedures in clinical practice. The TheraScreen K-RAS Mutation Kit identified mutations in 75 (44%) of the 170 tumors. Three cases were tested positive using TheraScreen K-RAS Mutation Kit and negative by direct sequencing. We then compared the sensitivity of the kit and that of direct sequencing using 74 mutant tumors. The kit was able to detect the presence of a mutation in a 1% dilution of the total DNA in 13.5% of the tumors and, in 84%, KRAS mutation was identified at a dilution of 5%. Sequencing was able to detect KRAS mutations when the mutant DNA represented 10% of the total DNA in 20/74 (27%) of the tumors. When the mutant DNA represented 30% of the total DNA, sequencing could detect mutations in 56/74 (76%). PMID:20203003

  16. Role-Playing and Real-Time Strategy Games Associated with Greater Probability of Internet Gaming Disorder.

    PubMed

    Eichenbaum, Adam; Kattner, Florian; Bradford, Daniel; Gentile, Douglas A; Green, C Shawn

    2015-08-01

    Research indicates that a small subset of those who routinely play video games show signs of pathological habits, with side effects ranging from mild (e.g., being late) to quite severe (e.g., losing a job). However, it is still not clear whether individual types, or genres, of games are most strongly associated with Internet gaming disorder (IGD). A sample of 4,744 University of Wisconsin-Madison undergraduates (Mage=18.9 years; SD=1.9 years; 60.5% female) completed questionnaires on general video game playing habits and on symptoms of IGD. Consistent with previous reports: 5.9-10.8% (depending on classification criteria) of individuals who played video games show signs of pathological play. Furthermore, real-time strategy and role-playing video games were more strongly associated with pathological play, compared with action and other games (e.g., phone games). The current investigation adds support to the idea that not all video games are equal. Instead, certain genres of video games, specifically real-time strategy and role-playing/fantasy games, are disproportionately associated with IGD symptoms. PMID:26252934

  17. Infrared absorption of methanethiol clusters (CH3SH)n, n = 2-5, recorded with a time-of-flight mass spectrometer using IR depletion and VUV ionization

    NASA Astrophysics Data System (ADS)

    Fu, Lung; Han, Hui-Ling; Lee, Yuan-Pern

    2012-12-01

    We investigated IR spectra in the CH- and SH-stretching regions of size-selected methanethiol clusters, (CH3SH)n with n = 2-5, in a pulsed supersonic jet using infrared (IR)-vacuum ultraviolet (VUV) ionization. VUV emission at 132.50 nm served as the source of ionization in a time-of-flight mass spectrometer. Clusters were dissociated with light from a tunable IR laser before ionization. The variations in intensity of methanethiol cluster ions (CH3SH)n+ were monitored as the IR laser light was tuned across the range 2470-3100 cm-1. In the SH-stretching region, the spectrum of (CH3SH)2 shows a weak band near 2601 cm-1, red-shifted only 7 cm-1 from that of the monomer. In contrast, all spectra of (CH3SH)n, n = 3-5, show a broad band near 2567 cm-1 with much greater intensity. In the CH-stretching region, absorption bands of (CH3SH)2 are located near 2865, 2890, 2944, and 3010 cm-1, red-shifted by 3-5 cm-1 from those of CH3SH. These red shifts increase slightly for larger clusters and bands near 2856, 2884, 2938, and 3005 cm-1 were observed for (CH3SH)5. These spectral results indicate that the S-H...S hydrogen bond plays an important role in clusters with n = 3-5, but not in (CH3SH)2, in agreement with theoretical predictions. The absence of a band near 2608 cm-1 that corresponds to absorption of the non-hydrogen-bonded SH moiety and the large width of observed feature near 2567 cm-1 indicate that the dominant stable structures of (CH3SH)n, n = 3-5, have a cyclic hydrogen-bonded framework.

  18. Constraining the Sahara freshwater discharge during sapropel S5 time by a stable isotope record from the Greater Sirte

    NASA Astrophysics Data System (ADS)

    Zirks, Eleen; Kucera, Michal; Bachem, Paul; Schulz, Hartmut

    2016-04-01

    The Nile River and the Black Sea were long considered as the only significant eastern Mediterranean freshwater sources and therefore inferred as the primary agents promoting surface stratification associated with sapropel formation. Sapropel S5, deposited during the last interglacial, marks a time of possible movement of Homo sapiens out of Africa. Satellite images revealed the existence of ancient rivers that once ran through the Sahara desert and drained into the Gulf of Sirte. Anomalous Nd isotope records from sapropel S5 deposits indicate that these rivers may have been active during MIS 5e, implying another freshwater source into the eastern Mediterranean Sea during that period. To constrain the extent of freshwater discharge into the Mediterranean from the Kufrah River during MIS 5e, a new δ18O record of five planktonic foraminifera species was generated from sediment core GeoTü SL 96, located proximal to the assumed outflow of the Kufrah River. The record from core GeoTü SL 96 compared with seven other records from the eastern Mediterranean Sea reveal a pattern of oxygen isotope anomalies which implies that the Kufrah River delivered detectable amount of freshwater during the second part of sapropel S5. These results reinforce the hypothesis that Sahara river systems were active during MIS 5e, which has ramifications for the understanding of sapropel events, reconstruction of coastal landscape, and the better understanding of migration routes of early humans.

  19. Baltimore Supersite: Highly time- and size-resolved concentrations of urban PM 2.5 and its constituents for resolution of sources and immune responses

    NASA Astrophysics Data System (ADS)

    Ondov, J. M.; Buckley, T. J.; Hopke, P. K.; Ogulei, D.; Parlange, M. B.; Rogge, W. F.; Squibb, K. S.; Johnston, M. V.; Wexler, A. S.

    Protection of public health from the effects of air particulate matter (PM) requires measurements and methods that assess the PM chemical constituents, physical properties, and their sources. Sampling was conducted at three sites in the Baltimore area: a source-oriented (industrial) area in south Baltimore (FMC site), and two receptor area sites (Clifton Park and Ponca Street). FMC measurements were made for the initial 1-month of the project; Clifton measurements lasted for about 2 months, while measurements at Ponca Street lasted for about 9.5 months. Pollutant samples were collected at intervals ranging from 5 min to 1 h using semi-continuous monitors for PM 2.5 mass, sulfate, nitrate, elemental and organic carbon, particle number size distributions (10-20,000 nm), CO, NO x, O 3, 11 metals, and mass spectra of individual particles, throughout the project. In addition to standard meteorological measurements, a 3D-sonic anemometer and a LIDAR system were operated during selected periods as were a rotating drum impactor with 3- to 6-h resolution and a filter/PUF sampler for 3-h measurements of organic compounds. Standard speciation and FRM mass measurements were also made. This report describes the types of measurements that were made at the various sites of the Baltimore Supersite program as well as presents the summary statistics for some of the PM measurements that have been made. The measurements of aerosol mass, major components, and size distribution data for the three sites are compared. Results show comparable PM concentrations at Ponca Street and Clifton Park. Increased variability was observed at Ponca Street.

  20. The demonstration of 10 Gbit/s time division multiplexing and 2.5 Gchip/s quasi-synchronous electrical code division multiplexing access passive optical network prototype system

    NASA Astrophysics Data System (ADS)

    Liang, Siyuan; Wang, Liqian; Cao, Yingying; Wang, Zhen; Han, Yamei; Wang, Dao; Chen, Xue

    2012-04-01

    The authors propose a novel architecture of passive optical network (PON), which consists of time division multiplexing (TDM) based downstream (10 Gbit/s) and quasi-synchronization (Q-S) electrical code division multiplexing access (ECDMA) based upstream (2.5 Gchip/s), and realize the prototype of this TDM-ECDMA PON. The high speed (2.5 Gchip/s) all digital en/decoding of upstream have been achieved by field-programmable gate array in this prototype. The frames error rate (FER) free transmission of Q-S ECDMA based upstream is demonstrated after 20 km fiber link. Then receiver sensitivity of optical line terminal in upstream transmission can be improved ~6 dB by coding gain compared with traditional 2.5 Gbit/s TDM PON.

  1. Evaluation of a Sequential Spot Sampler (S3) for time-resolved measurement of PM2.5 sulfate and nitrate through lab and field measurements

    NASA Astrophysics Data System (ADS)

    Hecobian, A.; Evanoski-Cole, A.; Eiguren-Fernandez, A.; Sullivan, A. P.; Lewis, G. S.; Hering, S. V.; Collett, J. L., Jr.

    2015-10-01

    The Sequential Spot Sampler (S3), a newly developed instrument to collect aerosols for time resolved chemical composition measurements, was evaluated in the laboratory and field for the measurement of particulate sulfate and nitrate. The S3 uses a multi-temperature condensation growth tube to grow individual aerosols to droplets which are then deposited as a ~ 1 mm diameter dry spot at the end of the growth tube on a 100 μL well of a multi-well plate. The well plate advances automatically to provide a sequence of time-resolved samples. The collected aerosols are subsequently analyzed in the laboratory. The sample is concentrated during the collection process and the laboratory extraction and analysis steps can be automated. The well plate, as received from the field, is placed onto a needle-based autosampler that adds liquid for sample extraction and injects sample extract from each well onto an ion chromatograph for analysis. Laboratory evaluation for sulfate and nitrate ions showed that PEEK used as well plate material does not contribute any artifacts; a 60 min extraction procedure leads to the recovery of sulfate and nitrate from the dry spots at above 95 % extraction efficiency; and samples stored frozen and analyzed up to 23 months later show less than a 10 % change in sulfate and nitrate concentrations. In a month long field study conducted in Southern California, two S3s were deployed alongside a URG denuder/filter-pack and a Particle-Into-Liquid Sampler combined with an Ion Chromatograph (PILS-IC). Collocated S3 sampler concentrations compared by linear regression show good agreement with r2 = 0.99 and slope = 0.99 (±0.004) μg m-3 for sulfate and r2 = 0.99 and slope =1.0 (±0.006) μg m-3 for nitrate. When compared to the URG denuder/filter-pack and the PILS-IC, the S3 sulfate and nitrate concentrations yielded correlations above 0.84 for the square of the correlation coefficient and regression slopes close to one.

  2. Evaluation of the Sequential Spot Sampler (S3) for time-resolved measurement of PM2.5 sulfate and nitrate through lab and field measurements

    NASA Astrophysics Data System (ADS)

    Hecobian, A.; Evanoski-Cole, A.; Eiguren-Fernandez, A.; Sullivan, A. P.; Lewis, G. S.; Hering, S. V.; Collett, J. L., Jr.

    2016-02-01

    The Sequential Spot Sampler (S3), a newly developed instrument to collect aerosols for time-resolved chemical composition measurements, was evaluated in the laboratory and field for the measurement of particulate sulfate and nitrate. The S3 uses a multi-temperature condensation growth tube to grow individual aerosols to droplets which are then deposited as a ˜ 1 mm diameter dry spot at the end of the growth tube in a 100 µL well of a multi-well plate. The well plate advances automatically to provide a sequence of time-resolved samples. The collected aerosols are subsequently analyzed in the laboratory. The sample is concentrated during the collection process, and the laboratory extraction and analysis steps can be automated. The well plate, as received from the field, is placed onto a needle-based autosampler that adds liquid for sample extraction and injects sample extract from each well onto an ion chromatograph for analysis. Laboratory evaluation for sulfate and nitrate ions showed that poly ether ether ketone (PEEK) used as well plate material does not contribute any artifacts; a 60 min extraction procedure leads to the recovery of sulfate and nitrate from the dry spots at above 95 % extraction efficiency; and samples stored frozen and analyzed up to 23 months later show less than a 10 % change in sulfate and nitrate concentrations. The limit of detection was 0.5 µg m-3 for sulfate and 0.2 µg m-3 for nitrate for a 1 h sampling period. In a month-long field study conducted in southern California, two S3s were deployed alongside a URG denuder-filter-pack and a Particle-Into-Liquid Sampler combined with an Ion Chromatograph (PILS-IC). Collocated S3 sampler concentrations compared by linear regression show good agreement, with r2 = 0.99 and slope = 0.99 (±0.004) µg m-3 for sulfate and r2 = 0.99 and slope = 1.0 (±0.006) µg m-3 for nitrate. When compared to the URG denuder-filter-pack and the PILS-IC, the S3 sulfate and nitrate concentrations yielded

  3. Identifying Optimal Temporal Scale for the Correlation of AOD and Ground Measurements of PM2.5 to Improve the Model Performance in a Real-time Air Quality Estimation System

    NASA Technical Reports Server (NTRS)

    Li, Hui; Faruque, Fazlay; Williams, Worth; Al-Hamdan, Mohammad; Luvall, Jeffrey C.; Crosson, William; Rickman, Douglas; Limaye, Ashutosh

    2009-01-01

    Aerosol optical depth (AOD), an indirect estimate of particle matter using satellite observations, has shown great promise in improving estimates of PM 2.5 air quality surface. Currently, few studies have been conducted to explore the optimal way to apply AOD data to improve the model accuracy of PM 2.5 surface estimation in a real-time air quality system. We believe that two major aspects may be worthy of consideration in that area: 1) the approach to integrate satellite measurements with ground measurements in the pollution estimation, and 2) identification of an optimal temporal scale to calculate the correlation of AOD and ground measurements. This paper is focused on the second aspect on the identifying the optimal temporal scale to correlate AOD with PM2.5. Five following different temporal scales were chosen to evaluate their impact on the model performance: 1) within the last 3 days, 2) within the last 10 days, 3) within the last 30 days, 4) within the last 90 days, and 5) the time period with the highest correlation in a year. The model performance is evaluated for its accuracy, bias, and errors based on the following selected statistics: the Mean Bias, the Normalized Mean Bias, the Root Mean Square Error, Normalized Mean Error, and the Index of Agreement. This research shows that the model with the temporal scale of within the last 30 days displays the best model performance in this study area using 2004 and 2005 data sets.

  4. Professional Rugby Union players have a 60% greater risk of time loss injury after concussion: a 2-season prospective study of clinical outcomes

    PubMed Central

    Cross, Matthew; Kemp, Simon; Smith, Andrew; Trewartha, Grant; Stokes, Keith

    2016-01-01

    Aim To investigate incidence of concussion, clinical outcomes and subsequent injury risk following concussion. Methods In a two-season (2012/2013, 2013/2014) prospective cohort study, incidence of diagnosed match concussions (injuries/1000 h), median time interval to subsequent injury of any type (survival time) and time spent at each stage of the graduated return to play pathway were determined in 810 professional Rugby Union players (1176 player seasons). Results Match concussion incidence was 8.9/1000 h with over 50% occurring in the tackle. Subsequent incidence of any injury for players who returned to play in the same season following a diagnosed concussion (122/1000 h, 95% CI 106 to 141) was 60% higher (IRR 1.6, 95% CI 1.4 to 1.8) than for those who did not sustain a concussion (76/1000 h, 95% CI 72 to 80). Median time to next injury following return to play was shorter following concussion (53 days, 95% CI 41 to 64) than following non-concussive injuries (114 days, 95% CI 85 to 143). 38% of players reported recurrence of symptoms or failed to match their baseline neurocognitive test during the graduated return to play protocol. Summary and conclusions Players who returned to play in the same season after a diagnosed concussion had a 60% greater risk of time-loss injury than players without concussion. A substantial proportion of players reported recurrence of symptoms or failed to match baseline neurocognitive test scores during graduated return to play. These data pave the way for trials of more conservative and comprehensive graduated return to play protocols, with a greater focus on active rehabilitation. PMID:26626266

  5. Population cycles are highly correlated over long time series and large spatial scales in two unrelated species: Greater sage-grouse and cottontail rabbits

    USGS Publications Warehouse

    Fedy, B.C.; Doherty, K.E.

    2011-01-01

    Animal species across multiple taxa demonstrate multi-annual population cycles, which have long been of interest to ecologists. Correlated population cycles between species that do not share a predator-prey relationship are particularly intriguing and challenging to explain. We investigated annual population trends of greater sage-grouse (Centrocercus urophasianus) and cottontail rabbits (Sylvilagus sp.) across Wyoming to explore the possibility of correlations between unrelated species, over multiple cycles, very large spatial areas, and relatively southern latitudes in terms of cycling species. We analyzed sage-grouse lek counts and annual hunter harvest indices from 1982 to 2007. We show that greater sage-grouse, currently listed as warranted but precluded under the US Endangered Species Act, and cottontails have highly correlated cycles (r = 0. 77). We explore possible mechanistic hypotheses to explain the synchronous population cycles. Our research highlights the importance of control populations in both adaptive management and impact studies. Furthermore, we demonstrate the functional value of these indices (lek counts and hunter harvest) for tracking broad-scale fluctuations in the species. This level of highly correlated long-term cycling has not previously been documented between two non-related species, over a long time-series, very large spatial scale, and within more southern latitudes. ?? 2010 US Government.

  6. Kerb and urban increment of highly time-resolved trace elements in PM10, PM2.5 and PM1.0 winter aerosol in London during ClearfLo 2012

    NASA Astrophysics Data System (ADS)

    Visser, S.; Slowik, J. G.; Furger, M.; Zotter, P.; Bukowiecki, N.; Dressler, R.; Flechsig, U.; Appel, K.; Green, D. C.; Tremper, A. H.; Young, D. E.; Williams, P. I.; Allan, J. D.; Herndon, S. C.; Williams, L. R.; Mohr, C.; Xu, L.; Ng, N. L.; Detournay, A.; Barlow, J. F.; Halios, C. H.; Fleming, Z. L.; Baltensperger, U.; Prévôt, A. S. H.

    2014-06-01

    Ambient concentrations of trace elements with 2 h time resolution were measured in PM10-2.5, PM2.5-1.0 and PM1.0-0.3 size ranges at kerbside, urban background and rural sites in London during winter 2012. Samples were collected using rotating drum impactors (RDIs) and subsequently analysed with synchrotron radiation-induced X-ray fluorescence spectrometry (SR-XRF). Quantification of kerb and urban increments (defined as kerb-to-urban and urban-to-rural concentration ratios, respectively), and assessment of diurnal and weekly variability provided insight into sources governing urban air quality and the effects of urban micro-environments on human exposure. Traffic-related elements yielded the highest kerb increments, with values in the range of 11.6 to 18.5 for SW winds (3.6-9.4 for NE) observed for elements influenced by brake wear (e.g. Cu, Sb, Ba) and 5.6 to 8.0 for SW (2.6-6.5 for NE) for other traffic-related processes (e.g. Cr, Fe, Zn). Kerb increments for these elements were highest in the PM10-2.5 mass fraction, roughly 3 times that of the PM1.0-0.3 fraction. These elements also showed the highest urban increments (∼3.0), although no difference was observed between brake wear and other traffic-related elements. Traffic-related elements exhibited higher concentrations during morning and evening rush hour, and on weekdays compared to weekends, with the strongest trends observed at the kerbside site, and additionally enhanced by winds coming directly from the road, consistent with street canyon effects. Elements related to mineral dust (e.g. Al, Ca, Sr) showed significant influences from traffic-induced resuspension, as evidenced by moderate kerb (2.0-4.1 for SW, 1.4-2.1 for NE) and urban (1.7-2.3) increments and increased concentrations during peak traffic flow. Elements related to regional transport showed no significant enhancement at kerb or urban sites, with the exception of PM10-2.5 sea salt (factor of 1.5-2.0), which may be influenced by traffic

  7. Kerb and urban increment of highly time-resolved trace elements in PM10, PM2.5 and PM1.0 winter aerosol in London during ClearfLo 2012

    NASA Astrophysics Data System (ADS)

    Visser, S.; Slowik, J. G.; Furger, M.; Zotter, P.; Bukowiecki, N.; Dressler, R.; Flechsig, U.; Appel, K.; Green, D. C.; Tremper, A. H.; Young, D. E.; Williams, P. I.; Allan, J. D.; Herndon, S. C.; Williams, L. R.; Mohr, C.; Xu, L.; Ng, N. L.; Detournay, A.; Barlow, J. F.; Halios, C. H.; Fleming, Z. L.; Baltensperger, U.; Prévôt, A. S. H.

    2015-03-01

    Ambient concentrations of trace elements with 2 h time resolution were measured in PM10-2.5, PM2.5-1.0 and PM1.0-0.3 size ranges at kerbside, urban background and rural sites in London during winter 2012. Samples were collected using rotating drum impactors (RDIs) and subsequently analysed with synchrotron radiation-induced X-ray fluorescence spectrometry (SR-XRF). Quantification of kerb and urban increments (defined as kerb-to-urban and urban-to-rural concentration ratios, respectively), and assessment of diurnal and weekly variability provided insight into sources governing urban air quality and the effects of urban micro-environments on human exposure. Traffic-related elements yielded the highest kerb increments, with values in the range of 10.4 to 16.6 for SW winds (3.3-6.9 for NE) observed for elements influenced by brake wear (e.g. Cu, Sb, Ba) and 5.7 to 8.2 for SW (2.6-3.0 for NE) for other traffic-related processes (e.g. Cr, Fe, Zn). Kerb increments for these elements were highest in the PM10-2.5 mass fraction, roughly twice that of the PM1.0-0.3 fraction. These elements also showed the highest urban increments (~ 3.0), although no difference was observed between brake wear and other traffic-related elements. All elements influenced by traffic exhibited higher concentrations during morning and evening rush hours, and on weekdays compared to weekends, with the strongest trends observed at the kerbside site, and additionally enhanced by winds coming directly from the road, consistent with street canyon effects. Elements related to mineral dust (e.g. Al, Si, Ca, Sr) showed significant influences from traffic-induced resuspension, as evidenced by moderate kerb (3.4-5.4 for SW, 1.7-2.3 for NE) and urban (~ 2) increments and increased concentrations during peak traffic flow. Elements related to regional transport showed no significant enhancement at kerb or urban sites, with the exception of PM10-2.5 sea salt (factor of up to 2), which may be influenced by

  8. Evidence of transient species occurring in the reduction process of trivalent lanthanides under 2.5 MeV electron irradiation by in situ cathodoluminescence and time-resolved photoluminescence

    SciTech Connect

    Ollier, N.; Boizot, B.; L'Henoret, P.; Guillous, S.; Petite, G.

    2009-06-01

    In situ cathodoluminescence and time-resolved photoluminescence measurements were carried out on Sm-doped glasses during a 2.5 MeV electron irradiation. These experiments allow characterizing more precisely the mechanisms operating under irradiation and more specifically the reduction processes of Sm{sup 3+} to Sm{sup 2+} ions. Sm{sup 2+} emission lines appear in the first steps of the irradiation, however, the {sup 5}D{sub 0}->{sup 7}F{sub 0-2} emission lines of Sm{sup 2+} were not observed on the cathodoluminescence spectrum. Moreover, two sites of Sm{sup 2+} have been evidenced in the glasses; the formation of each species is clearly different. Relaxation processes of Sm{sup 3+} and Sm{sup 2+} leads to consider the existence of different transient states of Sm{sup 3+} and Sm{sup 2+} species which are annealed after irradiation. We propose some synthetic schemes of the reduction mechanisms produced during the irradiation.

  9. NQR studies on 2,5-dichlorophenol

    NASA Astrophysics Data System (ADS)

    Kasturi, Alapati; Venkatacharyulu, P.; Premaswarup, D.

    1990-11-01

    Nuclear quadrupole resonance (NQR) Zeeman effect studies were carried out on cylindrical single crystals of 2,5-dichlorophenol, using the two 35Cl-NQR frequencies. A self-quenched superregenerative NQR spectrometer was used, and the spectra were analysed ot obtain information on the nature of the crystalline unit cell. An analysis of the experimental data reveals that: (1) the results are in good agreement with the structural reports of Bavoux and Perrin; (2) the crystal unequivocally belongs to the monoclinic system; (3) there are two crystallographically equivalent but physically inequivalent directions for the principal field gradient axes for both the low- and high-frequency resonance lines; (4) as the number of physically inequivalent directions for each of the two resonance lines is two, the minimum number of molecules per unit cell is two; (5) the b axis (90°,90°) is identified as the symmetry axis; (6) the growth axis is slightly inclined to the c axis; (7) the asymmetry parameters obtained for the loci corresponding to the low-frequency line, which is hydrogen bonded, are greater than those for the high-frequency line, which is nonhydrogen bonded; (8) the double-bond character is greater for the hydrogen-bonded chlorine than for the non-hydrogen-bonded chlorine; (9) the ratios of the various bond characters estimated for both the low- and high-frequency resonance lines are 69:24:7 and 74:24:2.

  10. OBSERVABLE INDICATORS OF THE SENSITIVITY OF PM2.5 NITRATE TO EMISSION REDUCTIONS PART I: DERIVATION OF THE ADJUSTED GAS RATIO AND APPLICABILITY AT REGULATORY-RELEVANT TIME SCALES

    EPA Science Inventory

    Chemical transport models have frequently been used to evaluate the impacts of emission reductions on inorganic PM2.5. However, such models are limited in their accuracy by uncertain estimates of the spatial and temporal characterization of emissions and meteorology. Site-speci...

  11. The Internet Time Lag: Anticipating the Long-Term Consequences of the Information Revolution. A Report of the Annual Aspen Institute Roundtable on Information Technology (10th, Aspen, Colorado, August 2-5, 2001).

    ERIC Educational Resources Information Center

    Schwartz, Evan I.

    This is a report of the 10th annual Aspen Institute Roundtable on Information Technology (Aspen, Colorado, August 2-5, 2001). Participants were also polled after the events of September 11, and these comments have been integrated into the report. The mission of this report is to take a wide-ranging look at the trends that are defining the next new…

  12. Greater arch injuries.

    PubMed

    Shivanna, Deepak; Manjunath, Dayanand; Amaravathi, Rajkumar

    2014-12-01

    Dislocations and fracture dislocations of carpal bones are uncommon injuries which invariably poses challenges in the management. Perilunate fracture dislocations are the combination of ligamentous and osseous injury that involve the "greater arc" of the perilunate associated instability. Despite their severity, these injuries often go unrecognized in the emergency department leading to delayed diagnosis and treatment. A Prospective study was done from June 2008 to December 2013 in 15 cases of complex wrist injuries which included of greater arch injuries, perilunate fracture dislocation and one dorsal dislocation of Scaphoid. 10 cases of perilunate fracture dislocation underwent open reduction and internal fixation with Herbert screw and k-wire, 4 cases of greater arch injury underwent closed reduction and kwire fixation and one case of neglected dorsal dislocation underwent proximal row carpectomy. One patient had Sudecks osteodystrophy 1 had Scaphoid nonunion and 6 had median nerve compression. Overall outcome according to Mayo wrist score was 53 % excellent, 33 % good and 14 % fair. Greater arch injuries are difficult to treat because injuries to many ligaments are involved and failure to recognize early leads to persistent pain, disability and early onset of arthritis. Prompt recognition requires CT scan and MRI. Management requires reduction and multiple K-Wiring according to merits of the case. PMID:25414554

  13. Random variation in rectal position during radiotherapy for prostate cancer is two to three times greater than that predicted from prostate motion

    PubMed Central

    Harrison, K; Romanchikova, M; Parker, A; Sutcliffe, M; Bond, S; Thomas, S; Freeman, S; Jena, R; Bates, A; Burnet, N

    2014-01-01

    Objective: Radiotherapy for prostate cancer does not explicitly take into account daily variation in the position of the rectum. It is important to accurately assess accumulated dose (DA) to the rectum in order to understand the relationship between dose and toxicity. The primary objective of this work was to quantify systematic (Σ) and random (σ) variation in the position of the rectum during a course of prostate radiotherapy. Methods: The rectum was manually outlined on the kilo-voltage planning scan and 37 daily mega-voltage image guidance scans for 10 participants recruited to the VoxTox study. The femoral heads were used to produce a fixed point to which all rectal contours were referenced. Results: Σ [standard deviation (SD) of means] between planning and treatment was 4.2 mm in the anteroposterior (AP) direction and 1.3 mm left–right (LR). σ (root mean square of SDs) was 5.2 mm AP and 2.7 mm LR. Superior–inferior variation was less than one slice above and below the planning position. Conclusion: Our results for Σ are in line with published data for prostate motion. σ, however, was approximately twice as great as that seen for prostate motion. This suggests that DA may differ from planned dose in some patients treated with radiotherapy for prostate cancer. Advances in knowledge: This work is the first to use daily imaging to quantify Σ and σ of the rectum in prostate cancer. σ was found to be greater than published data, providing strong rationale for further investigation of individual DA. PMID:25138155

  14. The 2-Year Checkup on 10 SNe IIn Discovered by Spitzer to Exhibit Late-Time (is greater than 100 Day) IR Emission

    NASA Technical Reports Server (NTRS)

    Fox, Ori Dosovitz; Chevalier, R. A.; Skrutskie, A. V.; Filippenko, A. V.; Silverman, J. M.; Ganeshalingam, M.

    2012-01-01

    Two years ago, a warm Spitzer survey of sixty-eight SNe IIn identified between the years 1998-2008 discovered 10 events with unreported late-time infrared (IR) excesses, in some cases more than 5 years post-explosion. These data nearly double the database of existing mid-IR observations of SNe IIn and offer important clues regarding the SN circumstellar.

  15. Source apportionment of PM 2.5 in the southeastern United States using receptor and emissions-based models: Conceptual differences and implications for time-series health studies

    NASA Astrophysics Data System (ADS)

    Marmur, Amit; Park, Sun-Kyoung; Mulholland, James A.; Tolbert, Paige E.; Russell, Armistead G.

    Elevated levels of fine particulate matter (PM 2.5) have been associated with adverse effects on human health, but whether specific components of PM 2.5 are responsible for specific health effects is still under investigation. A complementary approach to examining species-specific associations is to assess associations between health outcomes and sources contributing to PM 2.5. This approach could help target and regulate the sources that contribute most to adverse health effects. Various techniques have been developed to quantify source impacts on air quality, allowing examination of their health impacts. We compare two conceptually different approaches to source apportionment (SA): a receptor model and an emissions-based air-quality model. Daily source impacts for July 2001 and January 2002 at four sites in the southeastern US were calculated using CMB-LGO, an extended chemical mass balance receptor model incorporating the Lipschitz global optimizer, and EPA's Models-3 emissions-based air-quality modeling system (MM5-SMOKE-community multiscale air-quality (CMAQ)). The receptor model captured more of the temporal variation in source impacts at a specific receptor site compared to the emissions-based model. Driven by data at a single site, receptor models may have some significant shortcomings with respect to spatial representativeness (unless a reduced study area is used or data from multiple sites are available). SA results from emissions-based models, such as CMAQ, may be more spatially representative as they represent an average grid-cell value. Limitations in the ability to model daily fluctuations in emissions, however, lead to results being driven mainly by regional meteorological trends, likely underestimating the true daily variations in local source impacts. Using results from either approach in a health study would likely introduce an attenuation of the observed association, due to limited spatial representativeness in receptor modeling results and to

  16. Greater Trochanteric Pain Syndrome.

    PubMed

    Redmond, John M; Chen, Austin W; Domb, Benjamin G

    2016-04-01

    Patients who have lateral hip pain historically have been diagnosed with trochanteric bursitis and treated with nonsteroidal anti-inflammatory medications, corticosteroid injections, and physical therapy. Although this strategy is effective for most patients, a substantial number of patients continue to have pain and functional limitations. Over the past decade, our understanding of disorders occurring in the peritrochanteric space has increased dramatically. Greater trochanteric pain syndrome encompasses trochanteric bursitis, external coxa saltans (ie, snapping hip), and abductor tendinopathy. A thorough understanding of the anatomy, examination findings, and imaging characteristics aids the clinician in treating these patients. Open and endoscopic treatment options are available for use when nonsurgical treatment is unsuccessful. PMID:26990713

  17. 36 CFR 2.5 - Research specimens.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Research specimens. 2.5 Section 2.5 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR RESOURCE PROTECTION, PUBLIC USE AND RECREATION § 2.5 Research specimens. (a) Taking plants, fish, wildlife, rocks or minerals except in accordance with...

  18. 39 CFR 2.5 - Authority.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Authority. 2.5 Section 2.5 Postal Service UNITED STATES POSTAL SERVICE THE BOARD OF GOVERNORS OF THE U.S. POSTAL SERVICE GENERAL AND TECHNICAL PROVISIONS (ARTICLE II) § 2.5 Authority. These bylaws are adopted by the Board under the authority conferred upon...

  19. 22 CFR 2.5 - Records.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Records. 2.5 Section 2.5 Foreign Relations DEPARTMENT OF STATE GENERAL PROTECTION OF FOREIGN DIGNITARIES AND OTHER OFFICIAL PERSONNEL § 2.5 Records. The... the Act of May 26, 1949, as amended (22 U.S.C. 2658))...

  20. 12 CFR 2.5 - Bank compensation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 1 2011-01-01 2011-01-01 false Bank compensation. 2.5 Section 2.5 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY SALES OF CREDIT LIFE INSURANCE § 2.5 Bank compensation. (a) Nothing contained in this part prohibits a bank employee, officer, director, or...

  1. 12 CFR 2.5 - Bank compensation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Bank compensation. 2.5 Section 2.5 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY SALES OF CREDIT LIFE INSURANCE § 2.5 Bank compensation. (a) Nothing contained in this part prohibits a bank employee, officer, director, or...

  2. 12 CFR 2.5 - Bank compensation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Bank compensation. 2.5 Section 2.5 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY SALES OF CREDIT LIFE INSURANCE § 2.5 Bank compensation. (a) Nothing contained in this part prohibits a bank employee, officer, director, or...

  3. 12 CFR 2.5 - Bank compensation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 1 2014-01-01 2014-01-01 false Bank compensation. 2.5 Section 2.5 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY SALES OF CREDIT LIFE INSURANCE § 2.5 Bank compensation. (a) Nothing contained in this part prohibits a bank employee, officer, director, or...

  4. 12 CFR 2.5 - Bank compensation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 1 2012-01-01 2012-01-01 false Bank compensation. 2.5 Section 2.5 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY SALES OF CREDIT LIFE INSURANCE § 2.5 Bank compensation. (a) Nothing contained in this part prohibits a bank employee, officer, director, or...

  5. Hemolymphangioma of Greater Omentum

    PubMed Central

    Pandey, Sagar; Fan, Miao; Chang, Dandan; Zhu, Junfeng; Zhu, Ying; Li, Ziping

    2016-01-01

    Abstract Hemolymphangioma is a rare vascular developmental error. It comprises malformed venous and lymphatic component in various proportion. To the best of our knowledge, only a few cases have been reported in the literature so far. Here, we report a case of huge intraperitoneal cystic mass in a 3-year-old boy that was presented to hospital with intractable abdominal pain. On examination, he had fever along with associated symptoms like cough and sputum. Abdomen was distended with no tenderness or rebound tenderness. On computed tomography scan, huge cystic mass was seen and was diagnosed as intraperitoneal benign cystic lesion. Excisional surgery of the lesion was planned. On surgery, lesion was found to be originated from greater omentum and no adhesion was seen in surrounding tissue. Complete excision of the lesion was done. Histopathological specimen after surgery suggested it to be hemolymphangioma. Follow-up for 6 months showed no recurrence. Hemolymphangioma of the greater omentum is benign tumor and accurate diagnosis before surgery is still a challenge. Presentation of disease may vary from simple well-defined cystic lesion to aggressive ill-defined lesion mimicking malignancy. Therefore, further research is needed to help doctor with preoperative radiological diagnosis and avoid unnecessary radical surgery. PMID:27124058

  6. More features, greater connectivity.

    PubMed

    Hunt, Sarah

    2015-09-01

    Changes in our political infrastructure, the continuing frailties of our economy, and a stark growth in population, have greatly impacted upon the perceived stability of the NHS. Healthcare teams have had to adapt to these changes, and so too have the technologies upon which they rely to deliver first-class patient care. Here Sarah Hunt, marketing co-ordinator at Aid Call, assesses how the changing healthcare environment has affected one of its fundamental technologies - the nurse call system, argues the case for wireless such systems in terms of what the company claims is greater adaptability to changing needs, and considers the ever-wider range of features and functions available from today's nurse call equipment, particularly via connectivity with both mobile devices, and ancillaries ranging from enuresis sensors to staff attack alert 'badges'. PMID:26548128

  7. Efficacy and safety of desloratadine/pseudoephedrine tablet, 2.5/120 mg two times a day, versus individual components in the treatment of patients with seasonal allergic rhinitis.

    PubMed

    Chervinsky, Paul; Nayak, Anjuli; Rooklin, Anthony; Danzig, Melvyn

    2005-01-01

    Although antihistamines are highly effective in alleviating many symptoms associated with seasonal allergic rhinitis (SAR), relief from nasal congestion is variable. The efficacy of desloratadine, an effective antihistamine, in combination with pseudoephedrine, a potent nasal decongestant, was evaluated to determine whether combination therapy was more effective than individual component therapy in reducing nasal congestion, as well as other SAR symptoms. This multicenter, randomized, double-blind, three-arm study included 650 patients with SAR. For 2 weeks, patients were administered a combination tablet of desloratadine plus pseudoephedrine (desloratadine/pseudoephedrine, 2.5/120 mg) twice per day (b.i.d.), desloratadine (5 mg) once per day, or pseudoephedrine (120 mg) b.i.d. Patients assessed the severity of their SAR symptoms twice daily on symptom diary cards. The primary variable-change from baseline in the reflective A.M./P.M. total symptom score, excluding nasal congestion-was significantly superior (-6.7) compared with desloratadine (-5.4) or pseudoephedrine (-5.3) alone (p < or = 0.001 versus either group). Secondary efficacy variables including total symptom scores (plus congestion), total nasal symptom scores, and total nonnasal symptom scores were significantly reduced after desloratadine/pseudoephedrine therapy compared with the individual components. The most frequently reported adverse events were insomnia, headache, and dry mouth. Desloratadine/pseudoephedrine, 2.5/120 mg b.i.d., therapy was more effective in reducing total symptom scores of SAR, including nasal congestion, than were the individual components. These results support the use of this combination therapy over desloratadine or pseudoephedrine alone. PMID:16450574

  8. Circadian biology: a 2.5 billion year old clock.

    PubMed

    Loudon, Andrew S I

    2012-07-24

    A recent study suggests that circadian clocks may have evolved at the time of the Great Oxidation Event 2.5 billion years ago in order to drive detoxification of reactive oxygen species. PMID:22835791

  9. 25 CFR 2.5 - Appeal bond.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Appeal bond. 2.5 Section 2.5 Indians BUREAU OF INDIAN... Appeal bond. (a) If a person believes that he/she may suffer a measurable and substantial financial loss as a direct result of the delay caused by an appeal, that person may request that the official...

  10. 25 CFR 2.5 - Appeal bond.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Appeal bond. 2.5 Section 2.5 Indians BUREAU OF INDIAN... Appeal bond. (a) If a person believes that he/she may suffer a measurable and substantial financial loss as a direct result of the delay caused by an appeal, that person may request that the official...

  11. 25 CFR 2.5 - Appeal bond.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Appeal bond. 2.5 Section 2.5 Indians BUREAU OF INDIAN... Appeal bond. (a) If a person believes that he/she may suffer a measurable and substantial financial loss as a direct result of the delay caused by an appeal, that person may request that the official...

  12. 25 CFR 2.5 - Appeal bond.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Appeal bond. 2.5 Section 2.5 Indians BUREAU OF INDIAN... Appeal bond. (a) If a person believes that he/she may suffer a measurable and substantial financial loss as a direct result of the delay caused by an appeal, that person may request that the official...

  13. 25 CFR 2.5 - Appeal bond.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Appeal bond. 2.5 Section 2.5 Indians BUREAU OF INDIAN... Appeal bond. (a) If a person believes that he/she may suffer a measurable and substantial financial loss as a direct result of the delay caused by an appeal, that person may request that the official...

  14. 28 CFR 2.5 - Sentence aggregation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Sentence aggregation. 2.5 Section 2.5 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT OF PRISONERS... aggregation. When multiple sentences are aggregated by the Bureau of Prisons pursuant to 18 U.S.C. 4161...

  15. Changes in time-use and drug use by young adults in poor neighbourhoods of Greater Buenos Aires, Argentina, after the political transitions of 2001-2002: Results of a survey

    PubMed Central

    2011-01-01

    Background In some countries, "Big Events" like crises and transitions have been followed by large increases in drug use, drug injection and HIV/AIDS. Argentina experienced an economic crisis and political transition in 2001/2002 that affected how people use their time. This paper studies how time use changes between years 2001 and 2004, subsequent to these events, were associated with drug consumption in poor neighbourhoods of Greater Buenos Aires. Methods In 2003-2004, 68 current injecting drug users (IDUs) and 235 young non-IDUs, aged 21-35, who lived in impoverished drug-impacted neighbourhoods in Greater Buenos Aires, were asked about time use then and in 2001. Data on weekly hours spent working or looking for work, doing housework/childcare, consuming drugs, being with friends, and hanging out in the neighbourhood, were studied in relation to time spent using drugs. Field observations and focus groups were also conducted. Results After 2001, among both IDUs and non-IDUs, mean weekly time spent working declined significantly (especially among IDUs); time spent looking for work increased, and time spent with friends and hanging out in the neighbourhood decreased. We found no increase in injecting or non-injecting drug consumption after 2001. Subjects most affected by the way the crises led to decreased work time and/or to increased time looking for work--and by the associated increase in time spent in one's neighbourhood--were most likely to increase their time using drugs. Conclusions Time use methods are useful to study changes in drug use and their relationships to every day life activities. In these previously-drug-impacted neighbourhoods, the Argentinean crisis did not lead to an increase in drug use, which somewhat contradicts our initial expectations. Nevertheless, those for whom the crises led to decreased work time, increased time looking for work, and increased time spent in indoor or outdoor neighbourhood environments, were likely to spend more time

  16. PLSS 2.5 Fan Design and Development

    NASA Technical Reports Server (NTRS)

    Converse, David; Carra, Michael; Quinn, Gregory; Chullen, Cinda

    2015-01-01

    NASA is building a high fidelity prototype of an advanced portable life support system (PLSS) as part of the Advanced Exploration Systems Program. This new PLSS, designated as PLSS 2.5, will advance component technologies and systems knowledge in order to inform a future flight program. The oxygen ventilation loop of its predecessor, PLSS 2.0, is driven by a centrifugal fan developed using specifications from over five years ago. PLSS technology and system parameters have matured to the point where the existing fan will not perform adequately for the new prototype. In addition, areas of potential improvement have been identified with the existing fan that could be addressed in a new design. As a result, a new fan was designed and tested for the PLSS 2.5. The PLSS 2.5 fan is a derivative of the one used in PLSS 2.0. It uses the same basic non-metallic can around the motor, but with a larger volute and impeller to meet the higher pressure drop requirements of the PLSS 2.5 loop. This allows it to operate at rotational speeds that are matched to rolling element bearings, and which create reasonably low impeller tip speeds. Development of the fan also considered a shrouded impeller design that allows larger clearances for greater oxygen safety and better performance.

  17. Waveform tomography in 2.5D: Parameterization for crooked-line acquisition geometry

    NASA Astrophysics Data System (ADS)

    Smithyman, B. R.; Clowes, R. M.

    2013-05-01

    A method for 2.5D viscoacoustic waveform tomography that can be applied to generate 2D models of velocity and attenuation from inversion of refraction waveforms on land seismic reflection data acquired along crooked roads is developed. It is particularly useful for typical crustal reflection surveys. First-arrival travel time tomography is applied using a 3D method, but with constraints on the intermediate 3D velocity model; the result is the starting model for the next step. A 2.5D frequency-domain full-waveform inversion stage parameterizes 3D geometry in the seismic source and receiver arrays, with the assumption that the velocity and attenuation models are homogeneous in the out-of-plane direction. This approach results in superior results compared to a strictly 2D approach when the acquisition line is crooked, with a moderate increase in computational cost. A case study using data acquired in the Nechako Basin in south-central British Columbia, Canada, exemplifies and validates the procedure. The velocity model derived from 2.5D waveform tomography is compared with that from a previous study in which 2D waveform tomography was applied to the same data set and with results from 3D travel time tomography. The resolution and accuracy of the velocity model from 2.5D waveform tomography are demonstrated to be greater than those from travel time or 2D waveform tomography. A model of viscoacoustic attenuation, which was not possible in the 2D case, is also generated. These models are interpreted jointly to highlight features of geological interest, such as a sedimentary basin, basement rocks, and faults, from surface to about 3 km depth.

  18. Weekly cycle of magnetic characteristics of PM2.5 and PM2.5-10 in Beijing, China

    NASA Astrophysics Data System (ADS)

    SHI, M.; Wu, H.; Zhang, S.; Li, H.; Yang, T.

    2013-12-01

    In urban areas,fine particle matter with aerodynamic diameter between 2.5 um and 10 um (PM2.5-10), and 2.5 um (PM2.5), as an important source of urban particulate matter (PM) pollutants, have significant negative effects on health, atmospheric visibility and climate. PM has increasingly become a significant index of indicating the atmospheric pollution of city. In recent years, Beijing, China has been listed as one of the most serious air pollution city in the world. In order to investigate the sources of air pollutants, a total of 283 pairs of PM2.5 and PM2.5-10 samples were collected daily from July, 2010 to June, 2011 in Beijing. Mineral magnetic properties and Scanning electron microscope (SEM) observations and energy dispersive X-ray spectroscopy (EDS) analyses of PM2.5 and PM2.5-10 were measured to verify the magnetic materials. Magnetic measures for PM indicated that the major magnetic phase was coarse-grained magnetite-like material. The χlf, χarm, SIRM and χarm/SIRM series of the PM2.5 and PM2.5-10 show seasonal dependences: high values in winter and low values in summer. In additional the parameters analyzed by Time-series methods show a strong cycle about 7 days above 95% confidence level. Weekly cycle of magnetic characteristics of PM2.5 and PM2.5-10 show different pattern: the concentration of magnetic particles in PM2.5-10 show high values in mid-week, and particle sizes is steady, while the concentration of magnetic particles in PM2.5 show reverse a weekly cycle pattern, and particle sizes is smaller in the mid-week.Microscopy analyses reveal basically three morphologies of magnetic grains: aggregate, spherules and angular particles. The ultrafine carbonaceous particles which tend to form complex clusters and chain-like structures, most likely come from coal burning and motor vehicle exhaust. Spherical particles in PM2.5 are dominantly composed of Fe, O and C, grain-diameters of particles range from 0.3 to 2 um. Angular particles of Fe

  19. Palladium-catalyzed 2,5-diheteroarylation of 2,5-dibromothiophene derivatives

    PubMed Central

    Belkessam, Fatma; Mohand, Aidene; Soulé, Jean-François

    2014-01-01

    Summary Conditions allowing the one pot 2,5-diheteroarylation of 2,5-dibromothiophene derivatives in the presence of palladium catalysts are reported. Using KOAc as the base, DMA as the solvent and only 0.5–2 mol % palladium catalysts, the target 2,5-diheteroarylated thiophenes were obtained in moderate to good yields and with a wide variety of heteroarenes such as thiazoles, thiophenes, furans, pyrroles, pyrazoles or isoxazoles. Moreover, sequential heteroarylation reactions allow the access to 2,5-diheteroarylated thiophenes bearing two different heteroaryl units. PMID:25550758

  20. Palladium-catalyzed 2,5-diheteroarylation of 2,5-dibromothiophene derivatives.

    PubMed

    Belkessam, Fatma; Mohand, Aidene; Soulé, Jean-François; Elias, Abdelhamid; Doucet, Henri

    2014-01-01

    Conditions allowing the one pot 2,5-diheteroarylation of 2,5-dibromothiophene derivatives in the presence of palladium catalysts are reported. Using KOAc as the base, DMA as the solvent and only 0.5-2 mol % palladium catalysts, the target 2,5-diheteroarylated thiophenes were obtained in moderate to good yields and with a wide variety of heteroarenes such as thiazoles, thiophenes, furans, pyrroles, pyrazoles or isoxazoles. Moreover, sequential heteroarylation reactions allow the access to 2,5-diheteroarylated thiophenes bearing two different heteroaryl units. PMID:25550758

  1. MCNPX version 2.5.c

    SciTech Connect

    Hendricks, J. S.

    2003-01-01

    MCNPX is a Fortran 90 Monte Carlo radiation transport computer code that transports all particles at all energies. It is a superset of MCNP4C3, and has many capabilities beyond MCNP4C3. These capabilities are summarized along with their quality guarantee and code availability. Then the user interface changes from MCNP are described. Finally, the n.ew capabilities of the latest version, MCNPX 2.5.c, are documented. Future plans and references are also provided.

  2. 1. Photocopy of photograph (original 2.5 x 2.5 inch negative ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Photocopy of photograph (original 2.5 x 2.5 inch negative located at Southern California Edison Company Corporate Offices, Rosemead, California). Photographer unknown, about 1950. PLANT 5 POWERHOUSE LOOKING UP NORTHEASTERN TAILRACE. VIEW TO SOUTHWEST. - Bishop Creek Hydroelectric System, Plant 5, Bishop Creek, Bishop, Inyo County, CA

  3. Fructose hydrogenation to 2,5-dimethyltetrahydrofuran over a sulfur-poisoned Pt/C catalyst

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The conversion of biomass to a suite of chemicals will allow for greater financial stability for a biorefinery and greater use of field residues from farms resulting in increased farm income. To that end, we have hydrogenated fructose to 2,5-dimethyltetrahydrofuran in 50% yield using 5%Pt/Carbon poi...

  4. BLOCKAGE 2.5 reference manual

    SciTech Connect

    Shaffer, C.J.; Brideau, J.; Rao, D.V.; Bernahl, W.

    1996-12-01

    The BLOCKAGE 2.5 code was developed by the US Nuclear Regulatory Commission (NRC) as a tool to evaluate license compliance regarding the design of suction strainers for emergency core cooling system (ECCS) pumps in boiling water reactors (BWR) as required by NRC Bulletin 96-03, ``Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in Boiling Water Reactors``. Science and Engineering Associates, Inc. (SEA) and Software Edge, Inc. (SE) developed this PC-based code. The instructions to effectively use this code to evaluate the potential of debris to sufficiently block a pump suction strainer such that a pump could lose NPSH margin was documented in a User`s Manual (NRC, NUREG/CR-6370). The Reference Manual contains additional information that supports the use of BLOCKAGE 2.5. It contains descriptions of the analytical models contained in the code, programmer guides illustrating the structure of the code, and summaries of coding verification and model validation exercises that were performed to ensure that the analytical models were correctly coded and applicable to the evaluation of BWR pump suction strainers. The BLOCKAGE code was developed by SEA and programmed in FORTRAN as a code that can be executed from the DOS level on a PC. A graphical users interface (GUI) was then developed by SEA to make BLOCKAGE easier to use and to provide graphical output capability. The GUI was programmed in the C language. The user has the option of executing BLOCKAGE 2.5 with the GUI or from the DOS level and the Users Manual provides instruction for both methods of execution.

  5. Abnormal reaction of 2,5-Dimethylfuran

    SciTech Connect

    Pevzner, L.M.; Ignat'ev, V.M.

    1987-09-20

    The authors have shown that the expected hydroxymethylation at position 3 of the furan ring does not occur in the reaction of 2,5-dimethylfuran with paraform in acetic acid at 70-80/sup 0/C with the dimethylfuran and paraform in molar ratios of 2:1-1:2, but the products from substitution in the side chain are formed. By vacuum distillation of the reaction mass the authors isolated 2-(5-methyl-2-furyl)- ethanol and a hygroscopic viscous product melting at 136/sup 0/C (5 mm Hg). The yield of the reaction products depends on the molar ratio of the dimethylfuran and paraform. The PMR spectrum of the product contains signals for the ..beta..-protons of the furan ring with chemical shifts of 5.81 and 5.90 ppm, a signal for the methyl group in the furan ring at 2.22 ppm, a doublet at 3.72 ppm with spin-spin coupling constant of 6 Hz, a weak quintet at 3.20 ppm with the same constant, and a broadened signal in the region of 4.66 ppm for the proton of the hydroxyl group.

  6. Source apportionment of PM2.5 in Incheon, Korea

    NASA Astrophysics Data System (ADS)

    Choi, J.; Ban, S.; Lee, C.; Yi, S.; Zoh, K.

    2011-12-01

    PM2.5 samples were collected at a centrally located urban monitoring site in Incheon, Korea, every third day from Jun 2009 to may 2010 and analyzed their chemical species. In this study, we investigated the source of PM2.5 using Positive Matrix Factorization(PMF), the source area from Potential Source Contribution Function (PSCF) and Conditional Probability Function(CPF), and characterized source variation among episode, non-episode, yellow sand events. Incheon, study site, is located at the mid-western tip of the Korean Peninsula with a population of 2.6 million people and area of 1029.4 km2, respectively. As a transportation hub, the city also holds the importance of meteological/geological aspect affecting the air quality of capital region, in that is prevailing westerlies zone and a air passageway from China to Japan passing through seoul, korea. In the study, the Four channel based on Annular Denuder System(ADS) were used for sample collection(URG co, USA). The filter samples were analyzed with respect to species type such as ion group, metal, and OC/EC compound using ion chromatography, ICP/MS, and NIOSH TOT method, respectively. The PM2.5 concentration was 43ug/m3 that is almost three times higher than the US NAAQS annual PM2.5 standard of 15ug/m3. Nine PM2.5 sources were resolved from PMF analysis that provided reasonable source profiles and interesting insights into the source contributions to the ambient mass concentrations. The major sources of PM2.5 were secondary nitrate(26.4%), secondary sulfate(17.3%), gasoline(16.4%), and residual oil combustion(13.5%), with lesser contributions from biomass burning (7.5%), road dust(6.9%), soil (5.5%), coal fire powerplant (4.0%), and free sea salt(2.4%). CPF results identified possible local source directions such as motor vehicles, free sea salt. PSCF results indicated that likely pollution areas increased secondary particle concentrations(sulfate and nitrate) in Incheon to be the major industrial areas in China

  7. Trading Accountability for Greater Flexibility.

    ERIC Educational Resources Information Center

    Sanders, Ted

    1991-01-01

    Describes the plight of two risk-taking principals who drastically improved their schools' academic performance, only to be defeated by bureaucratic regulations and business-as-usual attitudes. Allowing schools greater flexibility in exchange for increased accountability will free talented teachers and principals to restructure schools and solve…

  8. Paleotectonic and paleogeographic evolution of greater China

    SciTech Connect

    Yilmaz, P.O.; Norton, I.O.

    1996-12-31

    In this study, we utilize plate tectonic history of Central Asia to constrain understanding of sedimentary basin development and to show how regional scale tectonic events affect play elements for major basins of greater China. Tectonic framework and paleogeography are used as a constraint on models for basin formation, climate distribution and accommodation which in turn control distribution of reservoir, source, seal and trap. Greater China is an artifact of Phanerozoic tectonics. It has a protracted history of continental deformation as amalgamation of crustal blocks and island arc/subduction and accretion complexes occurred. Early Paleozoic hydrocarbon systems are dominated by extensive carbonate platform and Permian and younger systems are dominated by continental and lacustrine sedimentation. The basement of greater China consists of continental and accretion crust. The crustal blocks include South and North China, Indochina, Tibet and Tarim, and accretion blocks include the Altaids and Manchurides. The relative positions and interactions of these blocks during Paleozic and Mesozoic time resulted in formation of greater China. Final amalgamation and deformation occurred in Eocene time when India collided with Asia. The discussions consist of presentation of a model for tectonic evolution of these blocks and their paleogeography through Phanerozoic time. This is done with maps at 1:8 million scale covering nine time slices, three in the Paleozoic, three in the Mesozoic and three in the Cenozoic.

  9. Paleotectonic and paleogeographic evolution of greater China

    SciTech Connect

    Yilmaz, P.O.; Norton, I.O. )

    1996-01-01

    In this study, we utilize plate tectonic history of Central Asia to constrain understanding of sedimentary basin development and to show how regional scale tectonic events affect play elements for major basins of greater China. Tectonic framework and paleogeography are used as a constraint on models for basin formation, climate distribution and accommodation which in turn control distribution of reservoir, source, seal and trap. Greater China is an artifact of Phanerozoic tectonics. It has a protracted history of continental deformation as amalgamation of crustal blocks and island arc/subduction and accretion complexes occurred. Early Paleozoic hydrocarbon systems are dominated by extensive carbonate platform and Permian and younger systems are dominated by continental and lacustrine sedimentation. The basement of greater China consists of continental and accretion crust. The crustal blocks include South and North China, Indochina, Tibet and Tarim, and accretion blocks include the Altaids and Manchurides. The relative positions and interactions of these blocks during Paleozic and Mesozoic time resulted in formation of greater China. Final amalgamation and deformation occurred in Eocene time when India collided with Asia. The discussions consist of presentation of a model for tectonic evolution of these blocks and their paleogeography through Phanerozoic time. This is done with maps at 1:8 million scale covering nine time slices, three in the Paleozoic, three in the Mesozoic and three in the Cenozoic.

  10. Seasonal variability of PM2.5 composition and sources in the Klang Valley urban-industrial environment

    NASA Astrophysics Data System (ADS)

    Amil, Norhaniza; Talib Latif, Mohd; Firoz Khan, Md; Mohamad, Maznorizan

    2016-04-01

    This study investigates the fine particulate matter (PM2.5) variability in the Klang Valley urban-industrial environment. In total, 94 daily PM2.5 samples were collected during a 1-year campaign from August 2011 to July 2012. This is the first paper on PM2.5 mass, chemical composition and sources in the tropical environment of Southeast Asia, covering all four seasons (distinguished by the wind flow patterns) including haze events. The samples were analysed for various inorganic components and black carbon (BC). The chemical compositions were statistically analysed and the temporal aerosol pattern (seasonal) was characterised using descriptive analysis, correlation matrices, enrichment factor (EF), stoichiometric analysis and chemical mass closure (CMC). For source apportionment purposes, a combination of positive matrix factorisation (PMF) and multi-linear regression (MLR) was employed. Further, meteorological-gaseous parameters were incorporated into each analysis for improved assessment. In addition, secondary data of total suspended particulate (TSP) and coarse particulate matter (PM10) sampled at the same location and time with this study (collected by Malaysian Meteorological Department) were used for PM ratio assessment. The results showed that PM2.5 mass averaged at 28 ± 18 µg m-3, 2.8-fold higher than the World Health Organisation (WHO) annual guideline. On a daily basis, the PM2.5 mass ranged between 6 and 118 µg m-3 with the daily WHO guideline exceeded 43 % of the time. The north-east (NE) monsoon was the only season with less than 50 % sample exceedance of the daily WHO guideline. On an annual scale, PM2.5 mass correlated positively with temperature (T) and wind speed (WS) but negatively with relative humidity (RH). With the exception of NOx, the gases analysed (CO, NO2, NO and SO2) were found to significantly influence the PM2.5 mass. Seasonal variability unexpectedly showed that rainfall, WS and wind direction (WD) did not significantly correlate

  11. Bison in the greater Yellowstone

    USGS Publications Warehouse

    Meagher, Mary

    1994-01-01

    In the Greater Yellowstone Area, free-ranging bison occur in Jackson Hole, Wyoming, and Yellowstone National Park. The Yellowstone population is discussed, with emphasis on changes in numbers from approximately 400 in 1968 to about 3500 now. Major influences for change initially were natural; more recently the winter road system used by snowmobiles appeared to be the dominant factor. The situation is in a state of flux. Interagency planning is in progress to address management alternatives for conflicts outside the park.

  12. Cooled radiofrequency ablation for bilateral greater occipital neuralgia.

    PubMed

    Vu, Tiffany; Chhatre, Akhil

    2014-01-01

    This report describes a case of bilateral greater occipital neuralgia treated with cooled radiofrequency ablation. The case is considered in relation to a review of greater occipital neuralgia, continuous thermal and pulsed radiofrequency ablation, and current medical literature on cooled radiofrequency ablation. In this case, a 35-year-old female with a 2.5-year history of chronic suboccipital bilateral headaches, described as constant, burning, and pulsating pain that started at the suboccipital region and radiated into her vertex. She was diagnosed with bilateral greater occipital neuralgia. She underwent cooled radiofrequency ablation of bilateral greater occipital nerves with minimal side effects and 75% pain reduction. Cooled radiofrequency ablation of the greater occipital nerve in challenging cases is an alternative to pulsed and continuous RFA to alleviate pain with less side effects and potential for long-term efficacy. PMID:24716017

  13. [Autoerotic fatalities in Greater Dusseldorf].

    PubMed

    Hartung, Benno; Hellen, Florence; Borchard, Nora; Huckenbeck, Wolfgang

    2011-01-01

    Autoerotic fatalities in the Greater Dusseldorf area correspond to the relevant medicolegal literature. Our results included exclusively young to middle-aged, usually single men who were found dead in their city apartments. Clothing and devices used showed a great variety. Women's or fetish clothing and complex shackling or hanging devices were disproportionately frequent. In most cases, death occurred due to hanging or ligature strangulation. There was no increased incidence of underlying psychiatric disorders. In most of the deceased no or at least no remarkable alcohol intoxication was found. Occasionally, it may be difficult to reliably differentiate autoerotic accidents, accidents occurring in connection with practices of bondage & discipline, dominance & submission (BDSM) from natural death, suicide or homicide. PMID:22039693

  14. SU-E-J-09: Image Quality Comparison and Dose Quantification for 2.5 MV

    SciTech Connect

    Stowe, M; DiCostanzo, D; Ayan, A; Woollard, J; Gupta, N

    2015-06-15

    Purpose: To compare the image quality of the 2.5MV imaging beam (2.5X-IMB) to that of a 6MV beam and to quantify the imaging dose of a 2.5X-IMB for constancy as specified by AAPM TG-142 Methods: The image quality of the 2.5X-IMB was compared to the 6MV imaging beam using the SNC ImagePro MV-QA phantom and the Varian supplied Las Vegas phantom (LVP). High resolution (1280×1280×16, 2 frames at 1.5MU/frame) and low resolution (640×640×16, 2 frames at 0.75MU/frame) images were compared for each phantom. MV-QA phantom images were evaluated quantitatively, and the LVP images were evaluated qualitatively. The imaging dose for 2.5X-IMB was quantified using the procedure outlined in TG51. PTWCC13-31013 chambers were used to measure a percent depth dose (PDD) curve for the 2.5X-IMB. All the factors described in TG51 were calculated using the 2.5X-IMB and a PTW30013 farmer chamber. Results: A comparison between 2.5X-IMB and 6MV image quality was performed both visually and with DoseLab software. The optimal window and level were set for each image of the LVP by the user. Visual inspection showed greater contrast resolution with the 2.5MV beam, but no significant difference with the change in imaging resolution. DoseLab reported similar spatial resolutions between the two energies, but the contrast-to-noise ratio (CNR) was greater for 2.5MV. The PDDx(10cm) for a 10x10cm2 field was measured to be 51.5%. Although this PDD value is off the scale of Figure 4 in TG51, the trend of the curve corresponding to the PTW31003 (equivalent) chamber led to an approximate kQ value of 1.00. Conclusion: When compared to 6MV imaging, 2.5X-IMB results in a better CNR. At low resolution, the DoseLab results for the two energies are comparable, but visual analysis favors the 2.5X-IMB images. Imaging dose was quantified for the 2.5X-IMB after following the TG51 methodology with appropriate approximations.

  15. Intra-urban spatial variability of PM2.5-bound carbonaceous components

    PubMed Central

    Xie, Mingjie; Coons, Teresa L.; Dutton, Steven J.; Milford, Jana B.; Miller, Shelly L.; Peel, Jennifer L.; Vedal, Sverre; Hannigan, Michael P.

    2014-01-01

    The Denver Aerosol Sources and Health (DASH) study was designed to evaluate associations between PM2.5 species and sources and adverse human health effects. The DASH study generated a five-year (2003–2007) time series of daily speciated PM2.5 concentration measurements from a single, special-purpose monitoring site in Denver, CO. To evaluate the ability of this site to adequately represent the short term temporal variability of PM2.5 concentrations in the five county Denver metropolitan area, a one year supplemental set of PM2.5 samples was collected every sixth day at the original DASH monitoring site and concurrently at three additional sites. Two of the four sites, including the original DASH site, were located in residential areas at least 1.9 km from interstate highways. The other two sites were located within 0.3 km of interstate highways. Concentrations of elemental carbon (EC), organic carbon (OC), and 58 organic molecular markers were measured at each site. To assess spatial variability, site pairs were compared using the Pearson correlation coefficient (r) and coefficient of divergence (COD), a statistic that provides information on the degree of uniformity between monitoring sites. Biweekly co-located samples collected from July 2004 to September 2005 were also analyzed and used to estimate the uncertainty associated with sampling and analytical measurement for each species. In general, the two near-highway sites exhibited higher concentrations of EC, OC, polycyclic aromatic hydrocarbons (PAHs), and steranes than did the more residential sites. Lower spatial heterogeneity based on r and COD was inferred for all carbonaceous species after considering their divergence and lack of perfect correlations in co-located samples. Ratio–ratio plots combined with available gasoline- and diesel-powered motor vehicle emissions profiles for the region suggested a greater impact to high molecular weight (HMW) PAHs from diesel-powered vehicles at the near

  16. CARDIOVASCULAR MORTALITY IN PHOENIX: PM1 IS A BETTER INDICATOR THAN PM2.5.

    EPA Science Inventory

    EPA has obtained a 3-year database of particulate matter (PM) in Phoenix, AZ from 1995 - 1997 that includes elemental analysis by XRF of daily PM2.5. During this time period PM1 and PM2.5 TEOMs were run simultaneously for about 7 months during two periods of the year. Regressio...

  17. Concentration measurements and chemical composition of PM10-2.5 and PM2.5 at a coastal site in Beirut, Lebanon

    NASA Astrophysics Data System (ADS)

    Shaka', Huda; Saliba, Najat A.

    Emission measurements and chemical profiles of PM10-2.5 (coarse) and PM2.5 (fine) in Lebanon are reported for the months of February till May of 2003. A 4 month average of 76 μg m -3 for PM10-2.5 and 40 μg m -3 for PM2.5 compared well with East Mediterranean cities but was higher than most emission measurements reported for the West Mediterranean basin. Using the ATR-FTIR technique, the chemical composition of aerosols was identified. Inorganic ions such as SO 42-, NO 3-, SiO 42-, CO 32-, and NH 4+, showed higher concentrations of PM2.5 when compared to PM10-2.5. Organic functional groups like aliphatic carbons, alcohols, carbonyls, and organic nitrates were also detected. Higher concentrations of organic species, i.e. aliphatic hydrocarbons and long chains of alcoholic and carboxylic acid substances, were identified in PM2.5 while in PM10-2.5, higher water concentrations were observed. Comparison between the ATR spectra of samples collected on a "regular" and a "sandy" day clearly showed the increase of SiO 42- ions and calcium carbonate during the sand storm due to dust loading on the Teflon filters. This study is one of the few works that have reported emission measurements in the Eastern Mediterranean, complementing thereby the large amount of data available in the Western Mediterranean. More importantly, this paper establishes a comparison between the main constituents of PM10-2.5 and PM2.5 using ATR-infrared spectroscopy, for the first time. Understanding the composition of different aerosol size fractions in the atmosphere enables us to better predict detailed chemical environmental variations.

  18. Structural requirements of (2'-5') oligoadenylate for protein synthesis inhibition in human fibroblasts.

    PubMed Central

    Drocourt, J L; Dieffenbach, C W; Ts'o, P O; Justesen, J; Thang, M N

    1982-01-01

    The structural requirements of (2'-5')-oligoadenylic acid (pppA(2'p5'A)x, X greater than or equal to 1 or (2'-5'An) for inhibition of protein synthesis in cells were examined with a modified calcium-coprecipitation technique, using a series of trinucleotide analogs (pppA2'p5'A2'p5'N, N=rC, rG, rU, T, dC, dG, dA). In this system both the degree and the duration of the inhibition of protein synthesis were dependent on the added concentration of (2'-5')A3. Of all the heterotrimers, only the deoxy A derivative was active as an inhibitor of protein synthesis, while the other members of the analog series were found to have no inhibitory effects. In competition experiments between (2'-5')A3 and the non-active analogs, three heterotrimers were shown to reduce the activity of (2'-5')A3 in protein inhibition. In contrast, the dephosphorylated (2'-5')A3 had no inhibitory effect and was not effective in blocking (2'-5')A3. These results indicate that the 5'-terminal triphosphate is important for binding of (2'-5')A3 to the site of (2'-5')An action and the adenine base at the 2'-terminus is important for activating the machinery responsible for protein synthesis inhibition in the cells, most likely the (2'-5')An-activated nuclease. PMID:7079179

  19. Spatiotemporal Variability of Remotely Sensed PM2.5 Concentrations in China from 1998 to 2014 Based on a Bayesian Hierarchy Model

    PubMed Central

    Li, Junming; Jin, Meijun; Xu, Zheng

    2016-01-01

    With the rapid industrial development and urbanization in China over the past three decades, PM2.5 pollution has become a severe environmental problem that threatens public health. Due to its unbalanced development and intrinsic topography features, the distribution of PM2.5 concentrations over China is spatially heterogeneous. In this study, we explore the spatiotemporal variations of PM2.5 pollution in China and four great urban areas from 1998 to 2014. A space-time Bayesian hierarchy model is employed to analyse PM2.5 pollution. The results show that a stable “3-Clusters” spatial PM2.5 pollution pattern has formed. The mean and 90% quantile of the PM2.5 concentrations in China have increased significantly, with annual increases of 0.279 μg/m3 (95% CI: 0.083−0.475) and 0.735 μg/m3 (95% CI: 0.261−1.210), respectively. The area with a PM2.5 pollution level of more than 70 μg/m3 has increased significantly, with an annual increase of 0.26 percentage points. Two regions in particular, the North China Plain and Sichuan Basin, are experiencing the largest amounts of PM2.5 pollution. The polluted areas, with a high local magnitude of more than 1.0 relative to the overall PM2.5 concentration, affect an area with a human population of 949 million, which corresponded to 69.3% of the total population in 2010. North and south differentiation occurs in the urban areas of the Jingjinji and Yangtze Delta, and circular and radial gradient differentiation occur in the urban areas of the Cheng-Yu and Pearl Deltas. The spatial heterogeneity of the urban Jingjinji group is the strongest. Eighteen cities located in the Yangtze Delta urban group, including Shanghai and Nanjing, have experienced high PM2.5 concentrations and faster local trends of increasing PM2.5. The percentage of exposure to PM2.5 concentrations greater than 70 μg/m3 and 100 μg/m3 is increasing significantly. PMID:27490557

  20. Spatiotemporal Variability of Remotely Sensed PM2.5 Concentrations in China from 1998 to 2014 Based on a Bayesian Hierarchy Model.

    PubMed

    Li, Junming; Jin, Meijun; Xu, Zheng

    2016-01-01

    With the rapid industrial development and urbanization in China over the past three decades, PM2.5 pollution has become a severe environmental problem that threatens public health. Due to its unbalanced development and intrinsic topography features, the distribution of PM2.5 concentrations over China is spatially heterogeneous. In this study, we explore the spatiotemporal variations of PM2.5 pollution in China and four great urban areas from 1998 to 2014. A space-time Bayesian hierarchy model is employed to analyse PM2.5 pollution. The results show that a stable "3-Clusters" spatial PM2.5 pollution pattern has formed. The mean and 90% quantile of the PM2.5 concentrations in China have increased significantly, with annual increases of 0.279 μg/m³ (95% CI: 0.083-0.475) and 0.735 μg/m³ (95% CI: 0.261-1.210), respectively. The area with a PM2.5 pollution level of more than 70 μg/m³ has increased significantly, with an annual increase of 0.26 percentage points. Two regions in particular, the North China Plain and Sichuan Basin, are experiencing the largest amounts of PM2.5 pollution. The polluted areas, with a high local magnitude of more than 1.0 relative to the overall PM2.5 concentration, affect an area with a human population of 949 million, which corresponded to 69.3% of the total population in 2010. North and south differentiation occurs in the urban areas of the Jingjinji and Yangtze Delta, and circular and radial gradient differentiation occur in the urban areas of the Cheng-Yu and Pearl Deltas. The spatial heterogeneity of the urban Jingjinji group is the strongest. Eighteen cities located in the Yangtze Delta urban group, including Shanghai and Nanjing, have experienced high PM2.5 concentrations and faster local trends of increasing PM2.5. The percentage of exposure to PM2.5 concentrations greater than 70 μg/m³ and 100 μg/m³ is increasing significantly. PMID:27490557

  1. Status and characteristics of ambient PM2.5 pollution in global megacities.

    PubMed

    Cheng, Zhen; Luo, Lina; Wang, Shuxiao; Wang, Yungang; Sharma, Sumit; Shimadera, Hikari; Wang, Xiaoliang; Bressi, Michael; de Miranda, Regina Maura; Jiang, Jingkun; Zhou, Wei; Fajardo, Oscar; Yan, Naiqiang; Hao, Jiming

    2016-01-01

    Ambient PM2.5 pollution is a substantial threat to public health in global megacities. This paper reviews the PM2.5 pollution of 45 global megacities in 2013, based on mass concentration from official monitoring networks and composition data reported in the literature. The results showed that the five most polluted megacities were Delhi, Cairo, Xi'an, Tianjin and Chengdu, all of which had an annual average concentration of PM2.5 greater than 89μg/m(3). The five cleanest megacities were Miami, Toronto, New York, Madrid and Philadelphia, the annual averages of which were less than 10μg/m(3). Spatial distribution indicated that the highly polluted megacities are concentrated in east-central China and the Indo-Gangetic Plain. Organic matter and SNA (sum of sulfate, nitrate and ammonium) contributed 30% and 36%, respectively, of the average PM2.5 mass for all megacities. Notable seasonal variation of PM2.5 polluted days was observed, especially for the polluted megacities of China and India, resulting in frequent heavy pollution episodes occurring during more polluted seasons such as winter. Marked differences in PM2.5 pollution between developing and developed megacities require more effort on local emissions reduction as well as global cooperation to address the PM2.5 pollution of those megacities mainly in Asia. PMID:26891184

  2. 10 CFR 960.5-2-5 - Environmental quality.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Environmental quality. 960.5-2-5 Section 960.5-2-5 Energy... REPOSITORY Preclosure Guidelines Environment, Socioeconomics, and Transportation § 960.5-2-5 Environmental..., technical, social, economic, and environmental factors; and (2) the requirements specified in §...

  3. 10 CFR 960.5-2-5 - Environmental quality.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Environmental quality. 960.5-2-5 Section 960.5-2-5 Energy... REPOSITORY Preclosure Guidelines Environment, Socioeconomics, and Transportation § 960.5-2-5 Environmental... repository siting, construction, operation, closure, and decommissioning, and projected environmental...

  4. 10 CFR 960.5-2-5 - Environmental quality.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Environmental quality. 960.5-2-5 Section 960.5-2-5 Energy... REPOSITORY Preclosure Guidelines Environment, Socioeconomics, and Transportation § 960.5-2-5 Environmental... repository siting, construction, operation, closure, and decommissioning, and projected environmental...

  5. 10 CFR 960.4-2-5 - Erosion.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Erosion. 960.4-2-5 Section 960.4-2-5 Energy DEPARTMENT OF... Postclosure Guidelines § 960.4-2-5 Erosion. (a) Qualifying condition. The site shall allow the underground... consider the climatic, tectonic, and geomorphic evidence of rates and patterns of erosion in the...

  6. 10 CFR 960.4-2-5 - Erosion.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Erosion. 960.4-2-5 Section 960.4-2-5 Energy DEPARTMENT OF... Postclosure Guidelines § 960.4-2-5 Erosion. (a) Qualifying condition. The site shall allow the underground... consider the climatic, tectonic, and geomorphic evidence of rates and patterns of erosion in the...

  7. 10 CFR 960.4-2-5 - Erosion.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Erosion. 960.4-2-5 Section 960.4-2-5 Energy DEPARTMENT OF... Postclosure Guidelines § 960.4-2-5 Erosion. (a) Qualifying condition. The site shall allow the underground... consider the climatic, tectonic, and geomorphic evidence of rates and patterns of erosion in the...

  8. 10 CFR 960.4-2-5 - Erosion.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Erosion. 960.4-2-5 Section 960.4-2-5 Energy DEPARTMENT OF... Postclosure Guidelines § 960.4-2-5 Erosion. (a) Qualifying condition. The site shall allow the underground... consider the climatic, tectonic, and geomorphic evidence of rates and patterns of erosion in the...

  9. 10 CFR 960.4-2-5 - Erosion.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Erosion. 960.4-2-5 Section 960.4-2-5 Energy DEPARTMENT OF... Postclosure Guidelines § 960.4-2-5 Erosion. (a) Qualifying condition. The site shall allow the underground... consider the climatic, tectonic, and geomorphic evidence of rates and patterns of erosion in the...

  10. 10 CFR 960.5-2-5 - Environmental quality.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Environmental quality. 960.5-2-5 Section 960.5-2-5 Energy... REPOSITORY Preclosure Guidelines Environment, Socioeconomics, and Transportation § 960.5-2-5 Environmental... repository siting, construction, operation, closure, and decommissioning, and projected environmental...

  11. 45 CFR 1206.2-5 - Right to counsel.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 4 2013-10-01 2013-10-01 false Right to counsel. 1206.2-5 Section 1206.2-5 Public Welfare Regulations Relating to Public Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE GRANTS AND CONTRACTS-SUSPENSION AND TERMINATION AND DENIAL OF APPLICATION FOR REFUNDING Denial of Application for Refunding § 1206.2-5 Right...

  12. 43 CFR 3453.2-5 - Effect of partial assignment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Effect of partial assignment. 3453.2-5 Section 3453.2-5 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND... Assignment, Sublease or Otherwise § 3453.2-5 Effect of partial assignment. A transfer of full record-title...

  13. 4 CFR 2.5 - Prohibited personnel practices.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 4 Accounts 1 2012-01-01 2012-01-01 false Prohibited personnel practices. 2.5 Section 2.5 Accounts GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL SYSTEM PURPOSE AND GENERAL PROVISION § 2.5 Prohibited personnel... specifically required by Executive order to be kept secret in the interest of national defense or the...

  14. 4 CFR 2.5 - Prohibited personnel practices.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 4 Accounts 1 2014-01-01 2013-01-01 true Prohibited personnel practices. 2.5 Section 2.5 Accounts GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL SYSTEM PURPOSE AND GENERAL PROVISION § 2.5 Prohibited personnel... specifically required by Executive order to be kept secret in the interest of national defense or the...

  15. 4 CFR 2.5 - Prohibited personnel practices.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 4 Accounts 1 2013-01-01 2013-01-01 false Prohibited personnel practices. 2.5 Section 2.5 Accounts GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL SYSTEM PURPOSE AND GENERAL PROVISION § 2.5 Prohibited personnel... specifically required by Executive order to be kept secret in the interest of national defense or the...

  16. 4 CFR 2.5 - Prohibited personnel practices.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 4 Accounts 1 2011-01-01 2011-01-01 false Prohibited personnel practices. 2.5 Section 2.5 Accounts GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL SYSTEM PURPOSE AND GENERAL PROVISION § 2.5 Prohibited personnel... specifically required by Executive order to be kept secret in the interest of national defense or the...

  17. 16 CFR 2.5 - By whom conducted.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false By whom conducted. 2.5 Section 2.5 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE NONADJUDICATIVE PROCEDURES Inquiries; Investigations; Compulsory Processes § 2.5 By whom conducted. Inquiries and investigations are conducted under the...

  18. Canadian National Air Pollution Surveillance (NAPS) PM 2.5 speciation program: Methodology and PM 2.5 chemical composition for the years 2003-2008

    NASA Astrophysics Data System (ADS)

    Dabek-Zlotorzynska, Ewa; Dann, Tom F.; Kalyani Martinelango, P.; Celo, Valbona; Brook, Jeffrey R.; Mathieu, David; Ding, Luyi; Austin, Claire C.

    2011-01-01

    The Canadian National Air Pollution Surveillance (NAPS) network, monitoring criteria gases (CO, O 3, NO x, and SO 2), PM 2.5, PM 10, volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs) and particle chemical mass and composition, has been in operation for over 40 years. Since 1984 both fine (<2.5 μm - PM 2.5) and coarse (2.5-10 μm - PM 10-2.5) particle mass measurements have been made at NAPS network sites using dichotomous samplers. In January 2003, the NAPS PM 2.5 speciation program was initiated with the purpose of measuring all major components of PM 2.5, including ammonium nitrate, ammonium sulphate, metals, and organic and elemental carbon. The present paper describes the improved sampling (e.g. Teflon/Nylon filter packs for nitrate loss, and an active blank for each and every sample in the determination of positive organic carbon artifacts), and analytical methods used in the Canadian NAPS PM 2.5 speciation program. A detailed dataset was then analyzed for seasonal and geographical variations in the major components of 24-h time integrated PM 2.5 samples collected at eight urban and three rural measurement sites across Canada (2003-2008). Chemical mass reconstruction was used for assessment of the adequacy of selected sampling and chemical parameters as well as for the determination of the relative contributions of different compound classes to PM 2.5 mass. The highest frequency of PM 2.5 episodes exceeding 30 μg m -3 were observed in Ontario and southern Quebec. In general, the most important contributions to PM 2.5 mass were secondary aerosol sulphate and nitrate (38-63% for western sites and 3-44% for eastern sites), depending on the season. Organic matter (OM) was found to be the second most important component (21-45%), while particle-bound water (PBW) accounted for 6-12% of the PM 2.5 mass. Golden B.C. was an exception, exhibiting high levels of OM (60-70%) and low levels of PBW (˜3%).

  19. Holocene peatland initiation in the Greater Everglades

    NASA Astrophysics Data System (ADS)

    Dekker, Stefan; de Boer, Hugo; Dermody, Brian; Wagner-Cremer, Friederike; Wassen, Martin; Eppinga, Maarten

    2015-04-01

    The mechanisms involved in the initiation and development of the Greater Everglades peatland ecosystems in South Florida (USA) remain a topic of discussion. In this study, we present an overview of basal ages of peat deposits in South Florida, which shows two major episodes of peatland initiation between 7.0-4.5 kyr and 3.5-2.0 kyr. Our analysis of regional climate proxy datasets led to three alternative hypotheses that may explain the timing and duration of these two peatland initiation episodes: (1) decreased drainage due to relative sea level (RSL) rise during the Holocene (2) gradual increase in precipitation throughout the Holocene, and (3) a combination of increasing precipitation, rising RSL and oscillations in the climate system. We test whether these three hypotheses can explain the pattern of initiation and development of the Greater Everglades peatlands using models that simulate the non-linear processes involved in peat production and decomposition in combination with the local drainage conditions of Southern Florida. The model results suggest that RSL-rise alone cannot predict the onset of peat initiation in the Greater Everglades using our model setup. The model also implies that the climate was wet enough for peat development also during the early Holocene. The first two hypothesized mechanisms in combination with climate oscillations may explain the onset of peat accumulation at 8.2 kyr BP. The two-phased character of peat land initiation may be explained by the spatial distribution of local drainage conditions. As peatland development is highly non-linear, our model uncovers a mechanistic way how peats can suddenly shift from a dry high equilibrium to a wet low equilibrium resulting in lake formation as observed in paleo-ecological studies in the Greater Everglades.

  20. Exploring variability in pedestrian exposure to fine particulates (PM 2.5) along a busy road

    NASA Astrophysics Data System (ADS)

    Greaves, Stephen; Issarayangyun, Tharit; Liu, Qian

    In August 2006, pedestrian exposure to PM 2.5 was monitored along a busy roadway in Sydney, Australia. The objective of the campaign was to assess the factors affecting exposure at both an inter- and intra-trip level. PM 2.5 measurements were made at second-by-second intervals using a portable aerosol monitor, while simultaneously recording location with a personal GPS device. A digital voice recorder was used to record any events or circumstances, perceived to notably increase potential PM 2.5 levels. The average PM 2.5 concentration for the 39 trips conducted was 12.8 μg m -3, which while 40% higher than concurrent ambient measurements was well within proposed daily standards for Australia. Multivariate time-series methods were then applied to study the effects of various interventions on PM 2.5 at an intra-trip level while controlling for autocorrelation. Wind speed, traffic volumes and clearway operations (independent of traffic volumes) were found to be significant predictors in addition to the previous PM 2.5 concentrations. Sensitivity analysis showed doubling traffic volumes increased PM 2.5 concentrations by 26%, while each 5 km h -1 increase in wind speed increased PM 2.5 concentrations by 10%. Several PM 2.5 hotspots were identified where concentrations exceeded 100 μg m -3. These were attributed to specific traffic (intersections, trucks, buses) and non-traffic sources (pedestrians smoking), typically only lasting a few seconds.

  1. Source identification of ambient PM 2.5 during summer inhalation exposure studies in Detroit, MI

    NASA Astrophysics Data System (ADS)

    Morishita, Masako; Keeler, Gerald J.; Wagner, James G.; Harkema, Jack R.

    Particulate air pollution is associated with cardiopulmonary morbidity and mortality in heavily populated urban centers of the United States. Because ambient fine particulate matter (aerodynamic diameter ⩽2.5 μm; PM 2.5) is a complex mixture resulting from multiple sources and variable atmospheric conditions, it is difficult to identify specific components of PM 2.5 that are responsible for adverse health effects. During four consecutive summers from 2000 to 2003 we characterized the ambient gaseous and PM 2.5 air quality in an urban southwest Detroit community where childhood asthma hospitalization rates are more than twice the statewide average. Both integrated and continuous PM measurements together with gaseous air pollution measurements were performed using a mobile air research facility, AirCARE1, in which concurrent toxicological studies were being conducted. Chemical and physical characterizations of PM 2.5 as well as receptor modeling using positive matrix factorization (PMF) were completed. Results from PMF indicated that six major sources contributed to the observed ambient PM 2.5 mass during the summer months. Primary sources included (1) coal combustion/secondary sulfate aerosol, (2) motor vehicle/urban road dust, (3) municipal waste incinerators, (4) oil combustion/refineries, (5) sewage sludge incinerators, and (6) iron/steel manufacturing. Although the contribution of the coal/secondary sulfate aerosol source was greater than other factors, increased levels of urban PM 2.5 from local combustion sources were also observed. In addition to characterization of ambient PM 2.5 and their sources in southwest Detroit, this paper discusses possible associations of ambient PM 2.5 from local combustion sources, specifically incinerator and refinery emissions and the observed adverse health effects during the inhalation exposure campaigns.

  2. Source of Personal Exposure to PM2.5 among College Students in Beijing, China

    NASA Astrophysics Data System (ADS)

    Xie, Qiaorong; Zhu, Xianlei; Li, Xiang; Hui, Fan; Fu, Xianqiang; Zhang, Qiangbin

    2015-04-01

    The health risk from exposure to airborne particles arouses increasing public concern in Beijing, a megacity in China, where concentration of PM2.5 frequently exceeds the guideline values of World Health Organization (WHO). To investigate daily exposure to PM2.5, a personal exposure study was conducted for college students. The purpose of this study was to measure the daily PM2.5 personal exposures of students, to quantify the contributions of various microenvironments to personal exposure since students spend more than 85% of their time indoors, and to apportion the contributions of PM2.5 indoors origin and outdoor origin. In this work, a total of 320 paired indoor and outdoor PM2.5 samples were collected at eight types of microenvironments in both China University of Petroleum (suburban area) and Tsinghua University (urban area). The microenvironments were selected based on the time-activity diary finished by 1500 students from both universities. Simultaneously, the air exchange rate was measured in each microenvironment. PM2.5, elements, inorganic ions and polycyclic aromatic hydrocarbons in the samples were determined. The peak concentrations were observed in dinning halls, whereas PM2.5 in dormitories was the largest contributor to personal exposure because students spend more than half of a day there. Furthermore, source apportionment by positive matrix factorization (PMF) will be carried out to understand the source of personal exposure to PM2.5. Especially, efforts will be put on determing the contributions of primary combustion, secondary sulfate and organics, secondary nitrate, and mechanically generated PM, which present different infiltration behavior and are indoor PM2.5 of ambient origin, with help of air exchange rate data. The results would be benefit for refining the understanding of the contribution of PM2.5 of ambient (outdoor) origin to the daily PM2.5 personal exposures. Acknowledgments:This study has been funded by Beijing Municipal Commission

  3. Zircon SHRIMP U-Pb dating of metamorphic complexes in the conjunction of the Greater and Lesser Xing'an ranges, NE China: Timing of formation and metamorphism and tectonic implications

    NASA Astrophysics Data System (ADS)

    Miao, Laicheng; Zhang, Fuqin; Zhu, Mingshuai; Liu, Dunyi

    2015-12-01

    Metamorphic complexes, including the Luomahu, Xinkailing and Fengshuigouhe groups, are scattered in the conjunction of the Greater and the Lesser Xing'an ranges, NE China, and have long been interpreted to represent the Precambrian basement of the so-called "Xing'an" and "Songnen" blocks although reliable evidence is lacking. Thin-section examination and mineral assemblage indicate that the protoliths of these metamorphic rocks are mainly meta-sedimentary and meta-volcanic rocks and have experienced greenschist- to amphibolite-facies metamorphism and strong deformation. Zircon SHRIMP U-Pb dating results of the metamorphic complexes and associated pre- or syn-kinematic veins constrained the formation and metamorphic ages of the Luomahuo Group at 175 ± 3 Ma and 159 ± 3 Ma, the Xingkailing Group at 200 ± 2 Ma and 158 ± 3 Ma, and the Fengshuigouhe Group at between 230-310 Ma and 170 ± 3 Ma, respectively. Additionally, all these rocks contain some Late Paleozoic detrital or inherited zircons with ages between 290-390 Ma, but no Precambrian, even if Early Paleozoic, age information was detected from these metamorphic rocks. These new data suggest that the metamorphic complexes were formed during Mesozoic-Late Paleozoic period, rather than in Precambrian as previously inferred, and that all of them underwent metamorphism and deformation during Middle Jurassic between 170-160 Ma. Consequently, these metamorphic complexes are not basement rocks of the so-called Precambrian continental blocks. Instead, there are likely metamorphosed Late Paleozoic-Mesozoic accretionary complexes and/or arc terranes. These results, in combination with published data, illustrate an overall young trend from north to south in the tectonic evolution of the northern Xing'an region. Significantly, the Jurassic (170-160 Ma) metamorphism and deformation event firstly identified by this study from the metamorphic complexes likely recorded the coinstantaneous Mongol-Okhotsk collisional and

  4. Intercomparison and evaluation of four semi-continuous PM 2.5 sulfate instruments

    NASA Astrophysics Data System (ADS)

    Drewnick, F.; Schwab, J. J.; Hogrefe, O.; Peters, S.; Husain, L.; Diamond, D.; Weber, R.; Demerjian, K. L.

    The development and evaluation of time-resolved (minutes) measurement technologies to characterize the physical and chemical make up of ambient aerosols/particulate matter in the atmosphere are essential to our improved understanding of aerosol process science, source attribution, and population exposure. During the PMTACS-NY summer 2001 campaign in Queens/New York, a wide variety of on-line aerosol analysis instruments were deployed together with gas-phase and filter sampling techniques. Here, we report on the intercomparison of four semi-continuous PM 2.5 sulfate instruments and evaluation of these instruments with one set of 6 h and three sets of 24-h filter measurements, collected at the same site. The semi-continuous instruments were an aerosol mass spectrometer, a particle-into-liquid sampler coupled with ion chromatograph, a Rupprecht & Patashnick Sulfate Monitor (R&P 8400S), and a continuous sulfate monitor developed by George Allen at Harvard School of Public Health and built in the field by one of us (J.J.S.). We found an excellent almost one-to-one correlation between the four semi-continuous instruments with typical multiple R-squared values >0.9. In addition, the correlations of the semi-continuous data with the filter measurements are also highly linear ( R2 0.86-0.98) but the semi-continuous instruments recover only about 85% of the sulfate mass collected by the filter techniques. The most likely explanation for this deviation is a combination of positive sampling artifacts on the filters (collection of particles with diameter greater then 2.5 μm, oxidation/condensation processes on the filters) with negative biases of the semi-continuous measurements (inlet line losses, limited collection efficiency for small particles below ca. 0.1 μm).

  5. Characterization of PM 2.5, PM 2.5-10 and PM > 10 in ambient air, Yokohama, Japan

    NASA Astrophysics Data System (ADS)

    Khan, Md. Firoz; Shirasuna, Yuichiro; Hirano, Koichiro; Masunaga, Shigeki

    2010-04-01

    This study elucidated the characteristics of ambient PM 2.5, PM 2.5-10 and PM > 10 with water soluble ions, i.e., Cl -, NO 3-, SO 42-, Na +, NH 4+, K +, Mg 2+ and Ca 2+ and carbonaceous aerosol, i.e., EC and OC in above size fractions from the samples collected for the period of 2007-2008. The total numbers of PM 2.5, PM 2.5-10 and PM > 10 samples collected with MCI sampler were 91, 87 and 79, respectively. The ambient particulate samples were collected twice in a week for a period of 24 h at the roof of a three-storied building in Yokohama National University. The annual arithmetic mean concentrations of PM 2.5, PM 2.5-10 and PM > 10 were 20.6, 9.6 and 5.1 µg m - 3 , respectively. The results of the daily PM 2.5 concentrations indicated that 67% of the daily PM 2.5 exceeded USEPA National Ambient Air Quality Standards (NAAQS) (15 µg m - 3 ) while 95% in respect of WHO ambient air quality guidelines (10 µg m - 3 ). The concentrations of water soluble ions in PM 2.5, PM 2.5-10 and PM > 10 accounted for 40%, 31% and 19%, respectively. The estimation of non-sea-salt particles implies that the major sources of water soluble ions in PM 2.5 are anthropogenic. On the other hand, a large proportion of sea salt particles contributes to PM 2.5-10 and PM > 10 . Spearman correlation indicated that the concentrations of OC and EC in PM 2.5 can originate from similar type of sources. However, the concentration of OC and EC in PM 2.5-10 and PM > 10 can have multiple sources. In addition, some atmospheric reactions were also characterized in this study.

  6. The sensitivities of emissions reductions for the mitigation of UK PM2.5

    NASA Astrophysics Data System (ADS)

    Vieno, M.; Heal, M. R.; Williams, M. L.; Carnell, E. J.; Nemitz, E.; Stedman, J. R.; Reis, S.

    2016-01-01

    The reduction of ambient concentrations of fine particulate matter (PM2.5) is a key objective for air pollution control policies in the UK and elsewhere. Long-term exposure to PM2.5 has been identified as a major contributor to adverse human health effects in epidemiological studies and underpins ambient PM2.5 legislation. As a range of emission sources and atmospheric chemistry transport processes contribute to PM2.5 concentrations, atmospheric chemistry transport models are an essential tool to assess emissions control effectiveness. The EMEP4UK atmospheric chemistry transport model was used to investigate the impact of reductions in UK anthropogenic emissions of primary PM2.5, NH3, NOx, SOx or non-methane VOC on surface concentrations of PM2.5 in the UK for a recent year (2010) and for a future current legislation emission (CLE) scenario (2030). In general, the sensitivity to UK mitigation is rather small. A 30 % reduction in UK emissions of any one of the above components yields (for the 2010 simulation) a maximum reduction in PM2.5 in any given location of ˜ 0.6 µg m-3 (equivalent to ˜ 6 % of the modelled PM2.5). On average across the UK, the sensitivity of PM2.5 concentrations to a 30 % reduction in UK emissions of individual contributing components, for both the 2010 and 2030 CLE baselines, increases in the order NMVOC, NOx, SOx, NH3 and primary PM2.5; however there are strong spatial differences in the PM2.5 sensitivities across the UK. Consequently, the sensitivity of PM2.5 to individual component emissions reductions varies between area and population weighting. Reductions in NH3 have the greatest effect on area-weighted PM2.5. A full UK population weighting places greater emphasis on reductions of primary PM2.5 emissions, which is simulated to be the most effective single-component control on PM2.5 for the 2030 scenario. An important conclusion is that weighting corresponding to the average exposure indicator metric (using data from the 45

  7. Profiling the PM2.5 mass concentration vertical distribution in the boundary layer

    NASA Astrophysics Data System (ADS)

    Tao, Z.; Wang, Z.; Yang, S.; Shan, H.; Ma, X.; Zhang, H.; Zhao, S.; Liu, D.; Xie, C.; Wang, Y.

    2015-12-01

    Fine particle (PM2.5) affects human life and activities directly; the detection of PM2.5 mass concentration profile is very essential due to its practical and scientific meanings (such as, quantifying of air quality and its variability, and improving air quality forecast and assessment). But so far, it is difficult to detect PM2.5 mass concentration profile. The proposed methodology to study the relationship between aerosol extinction coefficient and PM2.5 mass concentration is described, which indicates that the PM2.5 mass concentration profile could be retrieved by combining a charge-coupled device (CCD) side-scatter lidar and a PM2.5 sampling detector. When the relative humidity is less than 70 %, PM2.5 mass concentration is proportional to aerosol extinction coefficient, and then the specific coefficient can be calculated. Using this specific coefficient, aerosol extinction profile is converted to PM2.5 mass concentration profile. Three cases of clean night (on 21 September 2014), pollutant night (on 17 March 2014), and heavy pollutant night (on 13 February 2015) are studied. The characteristic of PM2.5 mass concentration profile in near-ground during these three nights' cases in the western suburb of Hefei city was discussed. The PM2.5 air pollutant concentration is comparatively large in close surface varying with time and altitude. The experiment results show that the CCD side-scatter lidar combined with a PM2.5 detector is an effective and new method to explore pollutant mass concentration profile in near-ground.

  8. Profiling the PM2.5 mass concentration vertical distribution in the boundary layer

    NASA Astrophysics Data System (ADS)

    Tao, Zongming; Wang, Zhenzhu; Yang, Shijun; Shan, Huihui; Ma, Xiaomin; Zhang, Hui; Zhao, Sugui; Liu, Dong; Xie, Chenbo; Wang, Yingjian

    2016-04-01

    Fine particles (PM2.5) affect human life and activities directly; the detection of PM2.5 mass concentration profile is very essential due to its practical and scientific significance (such as the quantification of air quality and its variability as well as the assessment of improving air quality forecast). But so far, it has been difficult to detect PM2.5 mass concentration profile. The proposed methodology to study the relationship between aerosol extinction coefficient and PM2.5 mass concentration is described, which indicates that the PM2.5 mass concentration profile could be retrieved by combining a charge-coupled device (CCD) side-scatter lidar with a PM2.5 sampling detector. When the relative humidity is less than 70 %, PM2.5, mass concentration is proportional to the aerosol extinction coefficient, and then the specific coefficient can be calculated. Through this specific coefficient, aerosol extinction profile is converted to PM2.5 mass concentration profile. Three cases of clean night (on 21 September 2014), pollutant night (on 17 March 2014), and heavy pollutant night (on 13 February 2015) are studied. The characteristics of PM2.5 mass concentration profile at the near-ground level during the cases of these 3 nights in the western suburb of Hefei city were discussed. The PM2.5 air pollutant concentration is comparatively large close to the surface and varies with time and altitude. The experiment results show that the CCD side-scatter lidar combined with a PM2.5 detector is an effective and new method to explore pollutant mass concentration profile at the near-ground level.

  9. An Update on 2,5-Diketopiperazines from Marine Organisms

    PubMed Central

    Huang, Ri-Ming; Yi, Xiang-Xi; Zhou, Yuying; Su, Xiangdong; Peng, Yan; Gao, Cheng-Hai

    2014-01-01

    2,5-Diketopiperazines (2,5-DKPs) are an important category of structurally diverse cyclic dipeptides with prominent biological properties. These 2,5-DKPs have been obtained from a variety of natural resources, including marine organisms. Because of the increasing numbers and biological importance of these compounds, this review covers 90 marine originated 2,5-DKPs that were reported from 2009 to the first half-year of 2014. The review will focus on the structure characterizations, biological properties and proposed biosynthetic processes of these compounds. PMID:25532564

  10. Characterization of particulate, metallic elements of TSP, PM(2.5) and PM(2.5-10) aerosols at a farm sampling site in Taiwan, Taichung.

    PubMed

    Fang, Guor-Cheng; Chang, Cheng-Nan; Chu, Chia-Chium; Wu, Yuh-Shen; Fu, Peter Pi-Cheng; Yang, I-Lin; Chen, Ming-Hsiang

    2003-06-01

    Atmospheric aerosol particles and metallic concentrations were monitored at the Experimental Farm of Tunghai University (EFTU) sampling site in this study. Total suspended particulate matter (TSP) was collected by using a PS-1 sampler at the farm-sampling site, in central Taiwan, from July 2001 to April 2002. At the same time, PM(2.5) and PM(2.5-10) were also measured with a Universal sampler from January 2002 to April 2002. Only subjects with the most complete data records on TSP sampling (N=43) and PM(10) sampling (N=23) were used in this analysis. Taichung Industrial Park, Taichung Kang Road (traffic) and a Hospital Incinerator surround the Experimental Farm of Tunghai University. Atmospheric concentrations of metallic elements were analyzed by a flame atomic absorption spectrophotometer (AA-680/G). The results indicated that the metallic elements Mg, Cu and Mn were the largest components in the TSP fraction; the metallic elements Fe and Cd were the largest composition in the PM(2.5-10) fraction; however, the metallic elements Pb, Zn, Cr and Ni were the largest abundance in the PM(2.5) fraction. The atmospheric metallic elements in the TSP, PM(2.5) and PM(2.5-10) fractions came different emission sources, such as soil, traffic, industry and resuspended particles. PMID:12738209

  11. Effect of local and long-range transport emissions on the elemental composition of PM 10-2.5 and PM 2.5 in Beirut

    NASA Astrophysics Data System (ADS)

    Saliba, Najat A.; Kouyoumdjian, Hovig; Roumié, Mohamad

    The elemental composition of PM 10-2.5 and PM 2.5 were studied in winter, summer, stormy and non-stormy dates during a period extending from February 2004 till January 2005, in a populated area of Beirut. Results of PIXE analysis and enrichment factor (E.F.) calculation, using Si as a reference of crustal material, showed that crustal elements (E.F.<10) like Si, Ca, K, Ti, Mn and Fe were more abundant in PM 10-2.5 while enriched elements (E.F.>10) like S, Cu, Zn and Pb predominated in PM 2.5. In PM 10-2.5, concentrations of crustal elements increased during stormy episodes, all time high Ca concentrations were due to the abundance of calcite and limestone rocks in Lebanon, and increased Cl levels correlated with marine air masses. In PM 2.5, sulfur concentrations were more prominent in the summer due to the enhancement of photochemical reactions. Sources of sulfur were attributed to local, sea-water and long-range transport from Eastern Europe, with the latter being the most predominate. Anthropogenic elements like Cu and Zn were generated from worn brakes and tires in high traffic density area and spikes of Pb were directly linked to a southerly wind originated from Egypt and/or Israel as determined by the air trajectory HYSPLIT model. In brief, elemental variations depended on the regional variability of the transport pattern and the different removal rates of aerosols.

  12. Chemical characterization of outdoor and subway fine (PM(2.5-1.0)) and coarse (PM(10-2.5)) particulate matter in Seoul (Korea) by computer-controlled scanning electron microscopy (CCSEM).

    PubMed

    Byeon, Sang-Hoon; Willis, Robert; Peters, Thomas M

    2015-02-01

    Outdoor and indoor (subway) samples were collected by passive sampling in urban Seoul (Korea) and analyzed with computer-controlled scanning electron microscopy coupled with energy dispersive x-ray spectroscopy (CCSEM-EDX). Soil/road dust particles accounted for 42%-60% (by weight) of fine particulate matter larger than 1 µm (PM(2.5-1.0)) in outdoor samples and 18% of PM2.5-1.0 in subway samples. Iron-containing particles accounted for only 3%-6% in outdoor samples but 69% in subway samples. Qualitatively similar results were found for coarse particulate matter (PM(10-2.5)) with soil/road dust particles dominating outdoor samples (66%-83%) and iron-containing particles contributing most to subway PM(10-2.5) (44%). As expected, soil/road dust particles comprised a greater mass fraction of PM(10-2.5) than PM(2.5-1.0). Also as expected, the mass fraction of iron-containing particles was substantially less in PM(10-2.5) than in PM(2.5-1.0). Results of this study are consistent with known emission sources in the area and with previous studies, which showed high concentrations of iron-containing particles in the subway compared to outdoor sites. Thus, passive sampling with CCSEM-EDX offers an inexpensive means to assess PM(2.5-1.0) and PM(10-2.5) simultaneously and by composition at multiple locations. PMID:25689348

  13. Holocene peatland initiation in the Greater Everglades

    NASA Astrophysics Data System (ADS)

    Dekker, Stefan C.; Boer, Hugo J.; Dermody, Brian J.; Wagner-Cremer, Friederike; Wassen, Martin J.; Eppinga, Maarten B.

    2015-02-01

    The mechanisms involved in the initiation and development of the Greater Everglades peatland ecosystems remain a topic of discussion. In this study, we first present an overview of basal ages of peat deposits in South Florida, which shows two major episodes of peatland initiation between 7.0-4.5 kyr and 3.5-2.0 kyr. Our analysis of regional climate proxy data sets led to three alternative hypotheses that may explain the timing and duration of these two peatland initiation episodes: (1) decreased drainage due to relative sea level (RSL) rise during the Holocene, (2) gradual increase in precipitation throughout the Holocene, and (3) a combination of increasing precipitation, rising RSL, and oscillations in the climate system. We test whether these three hypotheses can explain the pattern of initiation and development of the Greater Everglades peatlands using models that simulate the nonlinear processes involved in peat production and decomposition. The model results suggest that RSL rise could explain the onset of peatland initiation and imply that the climate was wet enough for peat development also during the early Holocene. The first two hypothesized mechanisms in combination with climate oscillations may explain the onset of peat accumulation at 8.2 kyr B.P. The two-phased character of peatland initiation maybe explained by the spatial distribution of local drainage conditions. As peatland development is highly nonlinear, our model uncovers a mechanistic way how peats can suddenly shift from a dry high equilibrium to a wet low equilibrium resulting in lake formation as observed in paleoecological studies in the Greater Everglades.

  14. PM2.5 measurements in the Tennessee Valley region

    SciTech Connect

    Parkhurst, W.J.; Tanner, R.L. Weatherford, F.P.; Meagher, J.F.; Eatough, D.J.

    1998-12-31

    Although the monitoring and regulatory implementation schedules for the revised particulate matter (PM) National Ambient Air Quality Standard (NAAQS) remain uncertain, it is evident that the new NAAQS for particulate matter with aerodynamic diameter less than 2.5 m m (i.e., PM2.5 or PMFine) will be difficult for many parts of the country to attain. Since August 1982, the Tennessee Valley Authority (TVA) has collected more than 14 station-years of baseline fine (PM2.5) and coarse (PM2.5 to PM10) mass data using standard dichotomous samplers deployed at eight monitoring stations ranging from urban/industrial to rural/background. The seasonal and inter-site variability of these mass data (and sulfur data as available) are described. PM2.5 to PM10 ratios appropriate for the south-central US estimated, and historic PM2.5 levels are compared with the new NAAQS to identify the potential for compliance problems. Preliminary PM2.5 data from a prototype Federal Reference Method (FRM) PM2.5 monitoring network, established by TVA and Tennessee Valley regulatory partners in 1997 to measure current levels of PM2.5 are presented. An improved denuder-based semi-volatile sampler employing a Harvard University particle concentrator has been developed and field tested. Preliminary results indicate that a significant and highly variable fraction of organic material (from as little as 10% to more than 60%) in the PM2.5 aerosol may be lost. This leads to serious uncertainties in source attribution, environmental exposure, and the development of PM2.5 control strategies.

  15. Comparative covalent protein binding of 2,5-hexanedione and 3-acetyl-2,5-hexanedione in the rat.

    PubMed

    DeCaprio, Anthony P; Kinney, Elizabeth A; LoPachin, Richard M

    2009-01-01

    2,5-Hexanedione (HD) is the metabolite implicated in n-hexane neurotoxicity. This gamma-diketone reacts with protein lysine amines to form 2,5-dimethylpyrrole adducts. Pyrrole adduction of neurofilaments (NF) and/or other axonal proteins was proposed as a critical step in the neuropathy. While pyrrole adduction is widely accepted as necessary, subsequent pyrrole oxidation, which may result in protein cross-linking, was alternatively postulated as the critical mechanistic step. Previous studies have indicated that 3-acetyl-2,5-HD (AcHD), an analogue that forms pyrroles that do not oxidize, was not neurotoxic in rats. However, relative levels of pyrrole adduction of NF or other axonal proteins were not reported. In the present study, groups of 6 male Wistar rats were given saline, [1,6-(14)C]-HD (3 mmol/kg/d), or [5-(14)C]-AcHD (0.1 mmol/kg/d), i.p. for 21 d. HD- and AcHD-treated rats lost 10% and gained 14% body weight, respectively, compared to a 22% gain for control rats. At termination, HD- and AcHD-treated rats exhibited mean scores of 3.5 and 1.4, respectively, for hindlimb weakness (0-5 scale). Incorporation of radiolabel from HD was 27.8 +/- 3.9, 13.9 +/- 2.6, and 7.8 +/- 0.6 nmol/mg in plasma protein, purified globin, and axonal cytoskeletal proteins, respectively, compared to 0.6 +/- 0.1, 1.6 +/- 0.5, and 1.0 +/- 0.1 for AcHD. Binding of HD to the NF-L, -M, and -H subunit proteins from treated animals was 4-, 24-, and 13-fold higher, respectively, that that of AcHD, indicating differing stoichiometry and patterns of NF adduction for the two diketones. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of globin and NF proteins did not demonstrate protein cross-linking for either diketone at the dose levels and time period examined. These results indicate that that the lack of neurotoxicity previously reported for AcHD may reflect differences in adduct levels at critical axonal target sites rather than an inability to form cross

  16. Sources of PM(10) and PM (2.5) in Cairo's ambient air.

    PubMed

    Abu-Allaban, M; Lowenthal, D H; Gertler, A W; Labib, M

    2007-10-01

    A source attribution study was performed to assess the contributions of specific pollutant source types to the observed particulate matter (PM) levels in the greater Cairo Area using the chemical mass balance (CMB) receptor model. Three intensive ambient monitoring studies were carried out during the period of February 21-March 3, 1999, October 27-November 27, 1999, and June 8-June 26, 2002. PM(10), PM(2.5), and polycyclic aromatic hydrocarbons (PAHs) were measured on a 24-h basis at six sampling stations during each of the intensive periods. The six intensive measurement sites represented background levels, mobile source impacts, industrial impacts, and residential exposure. Major contributors to PM(10) included geological material, mobile source emissions, and open burning. PM(2.5) tended to be dominated by mobile source emissions, open burning, and secondary species. This paper presents the results of the PM(10) and PM(2.5), source contribution estimates. PMID:17268919

  17. AN ELECTROSTATIC SAMPLER FOR COLLECTING PM-2.5

    EPA Science Inventory

    Objective: Develop a new electrostatic sampler for collecting PM-2.5. This sampler will fit into the existing Federal Reference Method (FRM) sampling head, and will be used in place of the Teflon filter to collect the PM-2.5. The primary expected benefit of this sampler design...

  18. FINE PARTICLE MATTER (PM2.5) DESIGN VALUE

    EPA Science Inventory

    Fine particulate matter or PM2.5 (total mass of particles below 2.5 micron is diameter) is known to cause adverse health effects in humans. see the following websites for more information on air quality and data. http://www.epa.gov/airnow/ http://www.epa.gov/air/ http://www.epa....

  19. FINE PARTICLE MATTER (PM2.5) DESIGN VALUE 2020

    EPA Science Inventory

    Fine particulate matter or PM2.5 (total mass of particles below 2.5 micron is diameter) is known to cause adverse health effects in humans. see the following websites for more information on air quality and data. http://www.epa.gov/airnow/ http://www.epa.gov/air/ http://www.epa....

  20. 43 CFR 3453.2-5 - Effect of partial assignment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Effect of partial assignment. 3453.2-5 Section 3453.2-5 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MANAGEMENT OF EXISTING LEASES Transfers...

  1. 43 CFR 3453.2-5 - Effect of partial assignment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Effect of partial assignment. 3453.2-5 Section 3453.2-5 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MANAGEMENT OF EXISTING LEASES Transfers...

  2. 43 CFR 3453.2-5 - Effect of partial assignment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Effect of partial assignment. 3453.2-5 Section 3453.2-5 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MANAGEMENT OF EXISTING LEASES Transfers...

  3. 43 CFR 3861.2-5 - Amended mineral surveys.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Amended mineral surveys. 3861.2-5 Section... MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERAL PATENT APPLICATIONS Surveys and Plats § 3861.2-5 Amended mineral surveys. (a) Inasmuch as amended surveys are ordered only by...

  4. 43 CFR 3861.2-5 - Amended mineral surveys.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Amended mineral surveys. 3861.2-5 Section... MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERAL PATENT APPLICATIONS Surveys and Plats § 3861.2-5 Amended mineral surveys. (a) Inasmuch as amended surveys are ordered only by...

  5. 43 CFR 3861.2-5 - Amended mineral surveys.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Amended mineral surveys. 3861.2-5 Section... MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERAL PATENT APPLICATIONS Surveys and Plats § 3861.2-5 Amended mineral surveys. (a) Inasmuch as amended surveys are ordered only by...

  6. 43 CFR 3861.2-5 - Amended mineral surveys.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Amended mineral surveys. 3861.2-5 Section... MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERAL PATENT APPLICATIONS Surveys and Plats § 3861.2-5 Amended mineral surveys. (a) Inasmuch as amended surveys are ordered only by...

  7. 14 CFR Sec. 2-5 - Revenue and accounting practices.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Revenue and accounting practices. Sec. 2-5... General Accounting Provisions Sec. 2-5 Revenue and accounting practices. (a) Revenue accounting practices... physically verify the reliability of its passenger revenue accounting practice at least once each...

  8. Photochemistry Of 2,5-Diacyl-1, 4-Dimethylbenzenes

    NASA Technical Reports Server (NTRS)

    Meador, Michael A.

    1989-01-01

    Experiments described in report revealed potentially useful aspects of photochemistry of 2,5-dibenzoyl-1, 4-dimethylbenzene (DBX) and 2,5-diacetyl-1, 4-dimethylbenzene (DAX). Behavior of these compounds reminiscent of orthoalkylphenyl ketones, studied from similar perspective for more than two decades.

  9. 14 CFR Sec. 2-5 - Revenue and accounting practices.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Revenue and accounting practices. Sec. 2-5... General Accounting Provisions Sec. 2-5 Revenue and accounting practices. (a) Revenue accounting practices... physically verify the reliability of its passenger revenue accounting practice at least once each...

  10. 10 CFR 960.5-2-5 - Environmental quality.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Environmental quality. 960.5-2-5 Section 960.5-2-5 Energy... quality. (a) Qualifying condition. The site shall be located such that (1) the quality of the environment... decommissioning the quality of the environment in the affected area could not be adequately protected or...

  11. 43 CFR 3712.2-5 - Proof of publication.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Proof of publication. 3712.2-5 Section... Proceedings Under the Act § 3712.2-5 Proof of publication. After the period of newspaper publication has expired, the department or agency requesting the publication shall obtain from the office of the...

  12. 43 CFR 3712.2-5 - Proof of publication.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Proof of publication. 3712.2-5 Section... Proceedings Under the Act § 3712.2-5 Proof of publication. After the period of newspaper publication has expired, the department or agency requesting the publication shall obtain from the office of the...

  13. Chronic PM2.5 Exposure and Inflammation: Determining Sensitive Subgroups in Mid-life Women

    PubMed Central

    Ostro, Bart; Malig, Brian; Broadwin, Rachel; Basu, Rupa; Gold, Ellen B.; Bromberger, Joyce T.; Derby, Carol; Feinstein, Steven; Greendale, Gail A.; Jackson, Elizabeth A.; Kravitz, Howard M.; Matthews, Karen A.; Sternfeld, Barbara; Tomey, Kristin; Green, Robin R.; Green, Rochelle

    2015-01-01

    Background Several cohort studies report associations between chronic exposure to ambient fine particles (PM2.5) and cardiovascular mortality. Uncertainty exists about biological mechanisms responsible for this observation, but systemic inflammation has been postulated. In addition, the subgroups susceptible to inflammation have not been fully elucidated. Methods We investigated whether certain subgroups are susceptible to the effects of long-term exposure to PM2.5 on C-reactive protein (CRP), a marker of inflammation directly linked to subsequent cardiovascular disease. We used data from the SWAN cohort of 1,923 mid-life women with up to five annual repeated measures of CRP. Linear mixed and GEE models accounting for repeated measurements within an individual were used to estimate the effects of prior-year PM2.5 exposure on CRP. We examined CRP as a continuous and as binary outcome for CRP greater than 3 mg/l, a level of clinical significance. Results We found strong associations between PM2.5 and CRP among several subgroups. For example a 10 µg/m3 increase in annual PM2.5 more than doubled the risk of CRP greater than 3 mg/l in older diabetics, smokers and the unmarried. Larger effects were also observed among those with low income, high blood pressure, or who were using hormone therapy, with indications of a protective effects for those using statins or consuming moderate amounts of alcohol. Conclusions In this study, we observed significant associations between long-term exposure to PM2.5 and CRP in several susceptible subgroups. This suggests a plausible pathway by which exposure to particulate matter may be associated with increased risk of cardiovascular disease. PMID:24792413

  14. Fine particulate (PM2.5) dynamics during rapid urbanization in Beijing, 1973–2013

    NASA Astrophysics Data System (ADS)

    Han, Lijian; Zhou, Weiqi; Li, Weifeng

    2016-03-01

    PM2.5 has been given special concern in recent years when the air quality monitoring station started recording. However, long-term PM2.5 concentration dynamic analysis cannot be taken with the limited observations. We therefore estimated the PM2.5 concentration using meteorological visibility data in Beijing. We found that 71 ± 17% of PM10 were PM2.5, which contributed to visibility impairment (y = 332.26e‑0.232x R2 = 0.75, P < 0.05). We then reconstructed a time series of annual PM2.5 from 1973 to 2013, and examined its relationship with urbanization by indicators of population, gross domestic production (GDP), energy consumption, and number of vehicles. Concluded that 1) Meteorological conditions were not the major cause of PM2.5 increase from 1973 to 2013; 2) With population and GDP growth, PM2.5 increased significantly (R2 = 0.5917, P < 0.05 R2 = 0.5426, P < 0.05) 3) Intensive human activity could change air quality in a short period, as observed changes in the correlations of PM2.5 concentration with energy consumption and number of vehicles before and after 2004, respectively. The success of this research provides an easy way in reconstructing long-term PM2.5 concentration with limited PM2.5 observation and meteorological visibility, and insight the impact of urbanization on air quality.

  15. Fine particulate (PM2.5) dynamics during rapid urbanization in Beijing, 1973-2013.

    PubMed

    Han, Lijian; Zhou, Weiqi; Li, Weifeng

    2016-01-01

    PM2.5 has been given special concern in recent years when the air quality monitoring station started recording. However, long-term PM2.5 concentration dynamic analysis cannot be taken with the limited observations. We therefore estimated the PM2.5 concentration using meteorological visibility data in Beijing. We found that 71 ± 17% of PM10 were PM2.5, which contributed to visibility impairment (y = 332.26e(-0.232x); R(2) = 0.75, P < 0.05). We then reconstructed a time series of annual PM2.5 from 1973 to 2013, and examined its relationship with urbanization by indicators of population, gross domestic production (GDP), energy consumption, and number of vehicles. Concluded that 1) Meteorological conditions were not the major cause of PM2.5 increase from 1973 to 2013; 2) With population and GDP growth, PM2.5 increased significantly (R(2) = 0.5917, P < 0.05; R(2) = 0.5426, P < 0.05); 3) Intensive human activity could change air quality in a short period, as observed changes in the correlations of PM2.5 concentration with energy consumption and number of vehicles before and after 2004, respectively. The success of this research provides an easy way in reconstructing long-term PM2.5 concentration with limited PM2.5 observation and meteorological visibility, and insight the impact of urbanization on air quality. PMID:27031598

  16. Fine particulate (PM2.5) dynamics during rapid urbanization in Beijing, 1973–2013

    PubMed Central

    Han, Lijian; Zhou, Weiqi; Li, Weifeng

    2016-01-01

    PM2.5 has been given special concern in recent years when the air quality monitoring station started recording. However, long-term PM2.5 concentration dynamic analysis cannot be taken with the limited observations. We therefore estimated the PM2.5 concentration using meteorological visibility data in Beijing. We found that 71 ± 17% of PM10 were PM2.5, which contributed to visibility impairment (y = 332.26e−0.232x; R2 = 0.75, P < 0.05). We then reconstructed a time series of annual PM2.5 from 1973 to 2013, and examined its relationship with urbanization by indicators of population, gross domestic production (GDP), energy consumption, and number of vehicles. Concluded that 1) Meteorological conditions were not the major cause of PM2.5 increase from 1973 to 2013; 2) With population and GDP growth, PM2.5 increased significantly (R2 = 0.5917, P < 0.05; R2 = 0.5426, P < 0.05); 3) Intensive human activity could change air quality in a short period, as observed changes in the correlations of PM2.5 concentration with energy consumption and number of vehicles before and after 2004, respectively. The success of this research provides an easy way in reconstructing long-term PM2.5 concentration with limited PM2.5 observation and meteorological visibility, and insight the impact of urbanization on air quality. PMID:27031598

  17. Spatiotemporal Characterization of Ambient PM2.5 Concentrations in Shandong Province (China).

    PubMed

    Yang, Yong; Christakos, George

    2015-11-17

    China experiences severe particulate matter (PM) pollution problems closely linked to its rapid economic growth. Advancing the understanding and characterization of spatiotemporal air pollution distribution is an area where improved quantitative methods are of great benefit to risk assessment and environmental policy. This work uses the Bayesian maximum entropy (BME) method to assess the space-time variability of PM2.5 concentrations and predict their distribution in the Shandong province, China. Daily PM2.5 concentrations obtained at air quality monitoring sites during 2014 were used. On the basis of the space-time PM2.5 distributions generated by BME, we performed three kinds of querying analysis to reveal the main distribution features. The results showed that the entire region of interest is seriously polluted (BME maps identified heavy pollution clusters during 2014). Quantitative characterization of pollution severity included both pollution level and duration. The number of days during which regional PM2.5 exceeded 75, 115, 150, and 250 μg m(-3) varied: 43-253, 13-128, 4-66, and 0-15 days, respectively. The PM2.5 pattern exhibited an increasing trend from east to west, with the western part of Shandong being a heavily polluted area (PM2.5 exceeded 150 μg m(-3) during long time periods). Pollution was much more serious during winter than during other seasons. Site indicators of PM2.5 pollution intensity and space-time variation were used to assess regional uncertainties and risks with their interpretation depending on the pollutant threshold. The observed PM2.5 concentrations exceeding a specified threshold increased almost linearly with increasing threshold value, whereas the relative probability of excess pollution decreased sharply with increasing threshold. PMID:26501430

  18. CUMULATIVE PM2.5 EXPOSURE AND TELOMERE LENGTH IN WORKERS EXPOSED TO WELDING FUMES

    PubMed Central

    Wong, Jason Y. Y.; De Vivo, Immaculata; Lin, Xihong; Christiani, David C.

    2014-01-01

    Telomeres are genomic structures that reflect both mitotic history and biochemical trauma to the genome. Metals inherent in fine particulate matter (PM2.5) were shown to be genotoxic via oxidative damage. However, few studies investigated the induction time of cumulative PM2.5 exposure on telomere length in a longitudinal setting. Therefore, the purpose of this study was to assess the association between occupational PM2.5 exposure in various time windows and telomere length. The study population consisted of 48 boilermakers and the follow-up period was 8 yr. The main exposures were cumulative occupational PM2.5 in the month, year, and career prior to each blood draw, assessed via work history questionnaires and area air measures. Repeated telomere length measurements from leukocytes were assessed via real-time quantitative polymerase chain reaction (qPCR). Analysis was performed using linear mixed models controlling for confounders and white blood cell differentials. Cumulative PM2.5 exposure was treated continuously and categorized into quartiles, in separate analyses. At any follow-up time, for each milligram per cubic meter per hour increase in cumulative PM2.5 exposure in the prior month, there was a statistically significant decrease in relative telomere length of −0.04 units. When categorizing the exposure into quartiles, there was a significant negative association between telomere length and highest quartile of cumulative PM2.5 exposure in the prior month (−0.16). These findings suggest that genomic trauma to leukocyte telomeres was more consistent with recent occupational PM2.5 exposure, as opposed to cumulative exposure extending into the distant past. PMID:24627998

  19. Identification of potential source areas for elevated PM2.5, nitrate and sulfate concentrations

    NASA Astrophysics Data System (ADS)

    Heo, Jongbae; McGinnis, Jerome E.; de Foy, Benjamin; Schauer, James J.

    2013-06-01

    Extreme events or episodes of ambient fine particulate matter (PM2.5), in which daily mass concentrations are substantially higher than annual averages, have been frequently observed in southern Wisconsin, US. Determining the cause of events has been a great challenge to local governments responsible for protecting public health and complying with the 24-h PM2.5 standard. This study analyzed air parcel movements originating from emission source areas, and trends in PM2.5 concentrations in order to determine the important factors involved in elevated PM2.5 episodes in the region. A single backward trajectory analysis coupled with PM2.5 concentrations observed at Federal Reference Method Network (FRM) sites in Madison, Milwaukee and Waukesha; and nitrate and sulfate concentrations monitored at a Chemical Speciation Network (CSN) site in Milwaukee, Wisconsin, from 2002 to 2010 were examined. The PM2.5 concentrations from the FRM showed the total PM2.5 mass during the episodes were higher in Madison than in Milwaukee and Waukesha, while annual average concentrations were lower in Madison. However, the temporal trend in frequency of elevated PM2.5 episodes was remarkably similar across sites during the entire study period and high frequency episodes occurring from 2005 to 2007. Residence time analysis of backward trajectories calculated for all recorded data indicated episode changes were mainly driven by year-to-year variations of air mass movements originating in high emissions areas. Potential Source Contribution Function (PSCF) results showed the extreme events of PM2.5 occurred during times when trajectories passed over ammonia emissions hotspots as well as large stationary emissions. Enhanced nitrate and sulfate concentrations which were the major episode components were strongly influenced by air masses trajectories originating from the Ohio River Valley and adjacent states.

  20. Synthesis of 2,5-Dichloro-2,5-Dimethylhexane by an S[subscript N]1 Reaction

    ERIC Educational Resources Information Center

    Wagner, Carl E.; Marshall, Pamela A.

    2010-01-01

    This laboratory experiment was developed to provide a safe, economical, and effective way to instruct undergraduate organic chemistry students about the unimolecular nucleophilic substitution (S[subscript N]1) reaction. Students treat 2,5-dimethyl-2,5-hexanediol with excess concentrated hydrochloric acid to synthesize…

  1. Addressing Global Mortality from Ambient PM2.5.

    PubMed

    Apte, Joshua S; Marshall, Julian D; Cohen, Aaron J; Brauer, Michael

    2015-07-01

    Ambient fine particulate matter (PM2.5) has a large and well-documented global burden of disease. Our analysis uses high-resolution (10 km, global-coverage) concentration data and cause-specific integrated exposure-response (IER) functions developed for the Global Burden of Disease 2010 to assess how regional and global improvements in ambient air quality could reduce attributable mortality from PM2.5. Overall, an aggressive global program of PM2.5 mitigation in line with WHO interim guidelines could avoid 750 000 (23%) of the 3.2 million deaths per year currently (ca. 2010) attributable to ambient PM2.5. Modest improvements in PM2.5 in relatively clean regions (North America, Europe) would result in surprisingly large avoided mortality, owing to demographic factors and the nonlinear concentration-response relationship that describes the risk of particulate matter in relation to several important causes of death. In contrast, major improvements in air quality would be required to substantially reduce mortality from PM2.5 in more polluted regions, such as China and India. Moreover, forecasted demographic and epidemiological transitions in India and China imply that to keep PM2.5-attributable mortality rates (deaths per 100 000 people per year) constant, average PM2.5 levels would need to decline by ∼20-30% over the next 15 years merely to offset increases in PM2.5-attributable mortality from aging populations. An effective program to deliver clean air to the world's most polluted regions could avoid several hundred thousand premature deaths each year. PMID:26077815

  2. Chemical identification of 2,5-dimethoxy-4-bromoamphetamine (DOB).

    PubMed

    da Costa, José Luiz; Wang, Alexandre Yautin; Micke, Gustavo Amadeu; Maldaner, Adriano Otávio; Romano, Renato Lahos; Martins-Júnior, Helio Alves; Negrini Neto, Osvaldo; Tavares, Marina Franco Maggi

    2007-12-20

    The consumption of synthetic drugs, generally known as designer drugs, has increased drastically in all parts of the world. Typical constituents of designer synthetic drugs are chemical substances derived from amphetamine but significant differences in effects caused and duration may result. In May, 2005, the civil state police of Sao Paulo seized thirty-one gelatinous capsules containing a very small quantity of a white powder inside (approximately 1.5 mg per capsule). This paper describes the analytical assays that were used to identify the seized material. Preliminary assays using colorimetric tests and high performance thin-layer chromatography indicated that the capsules content could be an amphetamine derivative. In the capillary zone electrophoresis assay, it was possible to observe that the analyzed material had basic characteristics. Mass spectrometry analysis revealed that the compound had the same molecular mass as 2,5-dimethoxy-4-bromoamphetamine (DOB) and its identity was confirmed through collision-induced dissociation (CID) experiments. Finally, the comparison of infrared sample spectrum with a spectra library provided further evidence of the DOB presence in the seized material. Although a reference standard material was not available, the information gathered from the different assays allowed the conclusion that the substance was, in fact, DOB, a substance with a powerful hallucinogenic action of proscribed use in the country and which was seized and identified for the first time in Brazil. PMID:17376619

  3. Friction model of the 2.5-mts SDSS telescope

    NASA Astrophysics Data System (ADS)

    Rivetta, Claudio H.; Hansen, Sten

    1998-05-01

    The 2.5mts telescope designed for the Sloan Digital Sky Survey is a mechancial structure that presents five degree- of-freedom. Azimuth, altitude and the instrument rotator axis are fitted with servo controls. The low frequency dynamic are dominated by the bearing friction. Several mathematical models have been presented in the literature to include its effect into the dynamic model of mechanical structures. The model employed in this paper includes consideration of the Striebeck effect, dynamic behavior at very low velocities and the pre-sliding at near zero- velocity. Result of the parameter estimation of the friction model of the three principle axes are presented as well as the behavior of the structure when different torque stimuli are applied. The mathematical model used to include the friction phenomena into the telescope dynamic model is simple. It does a good job of describing the friction over a wide range of velocities but particularly at or below sidereal rate. It is a straight forward process to determine the parameters and, in simulations, does not require large amounts of computer time.

  4. Friction model of the 2.5mts SDSS telescope

    SciTech Connect

    Rivetta, Claudio H.; Hansen, Sten

    1998-02-01

    The 2.5mts telescope designed for the Sloan Digital Sky Survey (SDSS) is a mechanical structure that presents five degree-of-freedom. Azimuth, altitude and the instrument rotator axis are fitted with servo controls. The low frequency dynamic are dominated by the bearing friction. Several mathematical models have been presented in the literature to include its effect into the dynamic model of mechanical structures. The model employed in this paper includes consideration of the Striebeck effect, dynamic behavior at very low velocities and the pre-sliding at near zero-velocity. Results of the parameter estimation of the friction model of the three principal axes are presented as well as the behavior of the structure when different torque stimuli are applied. The mathematical model used to include the friction phenomena into the telescope dynamic model is simple. It does a good job of describing the friction over a wide range of velocities but particularly at or below siderial rate. It is a straight forward process to determine the parameters and, in simulations, does not require large amounts of computer time. 10 refs. , 8 figs.

  5. Comparison of how ambient PMc and PM2.5 influence the inflammatory potential

    PubMed Central

    Ferguson, Matthew D.; Migliaccio, Chris; Ward, Tony

    2014-01-01

    Airborne particulate matter (PM) is one of six criteria air pollutants currently regulated by the U.S. Environmental Protection Agency (EPA), with existing ambient standards for PM2.5 and PM10. Currently there are no health-based regulations for the size fraction between 2.5 and 10 μm, commonly known as the coarse fraction (PMc). The present study investigates current gaps in knowledge for PMc including exposure toxicity and PM ratios (PMc:PM2.5) in PM10. Throughout the world, all three PM size fractions have been shown to be associated with adverse impacts. Recent studies have shown that PMc can be more detrimental to susceptible populations when directly compared to PM2.5, and that the PMc fraction in PM10 can account for the majority of the inflammatory response from PM10 exposure. In our studies we utilized a bone marrow-derived mouse macrophage in vitro system to compare the inflammatory potential of PMc, PM2.5, and mixtures of the two. The result was a linear increase in interleukin(IL) −1β with increasing levels of exposure to winter and summer PMc, as compared to PM2.5, which exhibited logarithmic growth. Also, exposure to PM10 as a function of PM2.5 and PMc mass ratios showed that IL-1β and TNF-α levels increased synergistically with a greater burden of PMc. Endotoxin content in the PM did not correlate with these results, suggesting that other activators in PMc are likely responsible for activating the NF-κB pathway and the inflammasome. PMID:24304303

  6. Black Carbon as an Additional Indicator of the Adverse Health Effects of Airborne Particles Compared with PM10 and PM2.5

    PubMed Central

    Hoek, Gerard; Simic-Lawson, Milena; Fischer, Paul; van Bree, Leendert; ten Brink, Harry; Keuken, Menno; Atkinson, Richard W.; Anderson, H. Ross; Brunekreef, Bert; Cassee, Flemming R.

    2011-01-01

    Background: Current air quality standards for particulate matter (PM) use the PM mass concentration [PM with aerodynamic diameters ≤ 10 μm (PM10) or ≤ 2.5 μm (PM2.5)] as a metric. It has been suggested that particles from combustion sources are more relevant to human health than are particles from other sources, but the impact of policies directed at reducing PM from combustion processes is usually relatively small when effects are estimated for a reduction in the total mass concentration. Objectives: We evaluated the value of black carbon particles (BCP) as an additional indicator in air quality management. Methods: We performed a systematic review and meta-analysis of health effects of BCP compared with PM mass based on data from time-series studies and cohort studies that measured both exposures. We compared the potential health benefits of a hypothetical traffic abatement measure, using near-roadway concentration increments of BCP and PM2.5 based on data from prior studies. Results: Estimated health effects of a 1-μg/m3 increase in exposure were greater for BCP than for PM10 or PM2.5, but estimated effects of an interquartile range increase were similar. Two-pollutant models in time-series studies suggested that the effect of BCP was more robust than the effect of PM mass. The estimated increase in life expectancy associated with a hypothetical traffic abatement measure was four to nine times higher when expressed in BCP compared with an equivalent change in PM2.5 mass. Conclusion: BCP is a valuable additional air quality indicator to evaluate the health risks of air quality dominated by primary combustion particles. PMID:21810552

  7. Fine particulate matter (PM2.5) in China at a city level

    PubMed Central

    Zhang, Yan-Lin; Cao, Fang

    2015-01-01

    This study presents one of the first long term datasets including a statistical summary of PM2.5 concentrations obtained from one-year monitoring in 190 cities in China. We found only 25 out of 190 cities could meet the National Ambient Air Quality Standards of China, and the population-weighted mean of PM2.5 in Chinese cities are 61 μg/m3, ~3 times as high as global population-weighted mean, highlighting a high health risk. PM2.5 concentrations are generally higher in north than in south regions due to relative large PM emissions and unfavorable meteorological conditions for pollution dispersion. A remarkable seasonal variability of PM2.5 is observed with the highest during the winter and the lowest during the summer. Due to the enhanced contributions from dust particles and open biomass burning, high PM2.5 abundances are also found in the spring (in Northwest and West Central China) and autumn (in East China), respectively. In addition, we found the lowest and highest PM2.5 often occurs in the afternoon and evening hours, respectively, associated with daily variation of the boundary layer depth and anthropogenic emissions. The diurnal distribution of the PM2.5-to-CO ratio consistently displays a pronounced peak during the afternoon periods, reflecting a significant contribution of secondary PM formation. PMID:26469995

  8. Fine particulate matter (PM2.5) in China at a city level

    NASA Astrophysics Data System (ADS)

    Zhang, Yan-Lin; Cao, Fang

    2015-10-01

    This study presents one of the first long term datasets including a statistical summary of PM2.5 concentrations obtained from one-year monitoring in 190 cities in China. We found only 25 out of 190 cities could meet the National Ambient Air Quality Standards of China, and the population-weighted mean of PM2.5 in Chinese cities are 61 μg/m3, ~3 times as high as global population-weighted mean, highlighting a high health risk. PM2.5 concentrations are generally higher in north than in south regions due to relative large PM emissions and unfavorable meteorological conditions for pollution dispersion. A remarkable seasonal variability of PM2.5 is observed with the highest during the winter and the lowest during the summer. Due to the enhanced contributions from dust particles and open biomass burning, high PM2.5 abundances are also found in the spring (in Northwest and West Central China) and autumn (in East China), respectively. In addition, we found the lowest and highest PM2.5 often occurs in the afternoon and evening hours, respectively, associated with daily variation of the boundary layer depth and anthropogenic emissions. The diurnal distribution of the PM2.5-to-CO ratio consistently displays a pronounced peak during the afternoon periods, reflecting a significant contribution of secondary PM formation.

  9. General 2.5 power law of metallic glasses.

    PubMed

    Zeng, Qiaoshi; Lin, Yu; Liu, Yijin; Zeng, Zhidan; Shi, Crystal Y; Zhang, Bo; Lou, Hongbo; Sinogeikin, Stanislav V; Kono, Yoshio; Kenney-Benson, Curtis; Park, Changyong; Yang, Wenge; Wang, Weihua; Sheng, Hongwei; Mao, Ho-Kwang; Mao, Wendy L

    2016-02-16

    Metallic glass (MG) is an important new category of materials, but very few rigorous laws are currently known for defining its "disordered" structure. Recently we found that under compression, the volume (V) of an MG changes precisely to the 2.5 power of its principal diffraction peak position (1/q1). In the present study, we find that this 2.5 power law holds even through the first-order polyamorphic transition of a Ce68Al10Cu20Co2 MG. This transition is, in effect, the equivalent of a continuous "composition" change of 4f-localized "big Ce" to 4f-itinerant "small Ce," indicating the 2.5 power law is general for tuning with composition. The exactness and universality imply that the 2.5 power law may be a general rule defining the structure of MGs. PMID:26831105

  10. Double-Sided 2.5D Graphics.

    PubMed

    Yeh, Chih-Kuo; Song, Peng; Lin, Peng-Yen; Fu, Chi-Wing; Lin, Chao-Hung; Lee, Tong-Yee

    2013-02-01

    This paper introduces double-sided 2.5D graphics, aiming at enriching the visual appearance when manipulating conventional 2D graphical objects in 2.5D worlds. By attaching a back texture image on a single-sided 2D graphical object, we can enrich the surface and texture detail on 2D graphical objects and improve our visual experience when manipulating and animating them. A family of novel operations on 2.5D graphics, including rolling, twisting, and folding, are proposed in this work, allowing users to efficiently create compelling 2.5D visual effects. Very little effort is needed from the user's side. In our experiment, various creative designs on double-sided graphics were worked out by the recruited participants including a professional artist, which show and demonstrate the feasibility and applicability of our proposed method. PMID:22529328

  11. General 2.5 power law of metallic glasses

    PubMed Central

    Zeng, Qiaoshi; Lin, Yu; Liu, Yijin; Zeng, Zhidan; Shi, Crystal Y.; Zhang, Bo; Lou, Hongbo; Sinogeikin, Stanislav V.; Kono, Yoshio; Kenney-Benson, Curtis; Park, Changyong; Yang, Wenge; Wang, Weihua; Sheng, Hongwei; Mao, Ho-kwang; Mao, Wendy L.

    2016-01-01

    Metallic glass (MG) is an important new category of materials, but very few rigorous laws are currently known for defining its “disordered” structure. Recently we found that under compression, the volume (V) of an MG changes precisely to the 2.5 power of its principal diffraction peak position (1/q1). In the present study, we find that this 2.5 power law holds even through the first-order polyamorphic transition of a Ce68Al10Cu20Co2 MG. This transition is, in effect, the equivalent of a continuous “composition” change of 4f-localized “big Ce” to 4f-itinerant “small Ce,” indicating the 2.5 power law is general for tuning with composition. The exactness and universality imply that the 2.5 power law may be a general rule defining the structure of MGs. PMID:26831105

  12. 41 CFR 51-2.5 - Committee decision.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Contracts COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED 2-COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED § 51-2.5 Committee decision. The Committee considers...

  13. 41 CFR 51-2.5 - Committee decision.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Contracts COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED 2-COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED § 51-2.5 Committee decision. The Committee considers...

  14. 41 CFR 51-2.5 - Committee decision.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Contracts COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED 2-COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED § 51-2.5 Committee decision. The Committee considers...

  15. 41 CFR 51-2.5 - Committee decision.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Contracts COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED 2-COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED § 51-2.5 Committee decision. The Committee considers...

  16. 41 CFR 51-2.5 - Committee decision.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Contracts COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED 2-COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED § 51-2.5 Committee decision. The Committee considers...

  17. Linking climate and air quality over Europe: effects of meteorology on PM2.5 concentrations

    NASA Astrophysics Data System (ADS)

    Megaritis, A. G.; Fountoukis, C.; Charalampidis, P. E.; Denier van der Gon, H. A. C.; Pilinis, C.; Pandis, S. N.

    2014-09-01

    The effects of various meteorological parameters such as temperature, wind speed, absolute humidity, precipitation and mixing height on PM2.5 concentrations over Europe were examined using a three-dimensional chemical transport model, PMCAMx-2008. Our simulations covered three periods, representative of different seasons (summer, winter, and fall). PM2.5 appears to be more sensitive to temperature changes compared to the other meteorological parameters in all seasons. PM2.5 generally decreases as temperature increases, although the predicted changes vary significantly in space and time, ranging from -700 ng m-3 K-1 (-8% K-1) to 300 ng m-3 K-1 (7% K-1). The predicted decreases of PM2.5 are mainly due to evaporation of ammonium nitrate, while the higher biogenic emissions and the accelerated gas-phase reaction rates increase the production of organic aerosol (OA) and sulfate, having the opposite effect on PM2.5. The predicted responses of PM2.5 to absolute humidity are also quite variable, ranging from -130 ng m-3 %-1 (-1.6% %-1) to 160 ng m-3 %-1 (1.6% %-1) dominated mainly by changes in inorganic PM2.5 species. An increase in absolute humidity favors the partitioning of nitrate to the aerosol phase and increases the average PM2.5 during summer and fall. Decreases in sulfate and sea salt levels govern the average PM2.5 response to humidity during winter. A decrease of wind speed (keeping the emissions constant) increases all PM2.5 species (on average 40 ng m-3 %-1) due to changes in dispersion and dry deposition. The wind speed effects on sea salt emissions are significant for PM2.5 concentrations over water and in coastal areas. Increases in precipitation have a negative effect on PM2.5 (decreases up to 110 ng m-3 %-1) in all periods due to increases in wet deposition of PM2.5 species and their gas precursors. Changes in mixing height have the smallest effects (up to 35 ng m-3 %-1) on PM2.5 . Regarding the relative importance of each of the meteorological

  18. Linking climate and air quality over Europe: effects of meteorology on PM2.5 concentrations

    NASA Astrophysics Data System (ADS)

    Megaritis, A. G.; Fountoukis, C.; Charalampidis, P. E.; Denier van der Gon, H. A. C.; Pilinis, C.; Pandis, S. N.

    2014-04-01

    The effects of various meteorological parameters such as temperature, wind speed, absolute humidity, precipitation and mixing height on PM2.5 concentrations over Europe were examined using a three-dimensional chemical transport model, PMCAMx-2008. Our simulations covered three periods, representative of different seasons (summer, winter, and fall). PM2.5 appears to be more sensitive to temperature changes compared to the other meteorological parameters in all seasons. PM2.5 generally decreases as temperature increases, although the predicted changes vary significantly in space and time, ranging from -700 ng m-3 K-1 (-8% K-1) to 300 ng m-3 K-1 (7% K-1). The predicted decreases of PM2.5 are mainly due to evaporation of ammonium nitrate, while the higher biogenic emissions and the accelerated gas-phase reaction rates increase the production of organic aerosol (OA) and sulfate, having the opposite effect on PM2.5. The predicted responses of PM2.5 to absolute humidity are also quite variable, ranging from -130 ng m-3%-1 (-1.6% %-1) to 160 ng m-3 %-1 (1.6% %-1) dominated mainly by changes in inorganic PM2.5 species. An increase in absolute humidity favors the partitioning of nitrate to the aerosol phase and increases the average PM2.5 during summer and fall. Decreases in sulfate and sea salt levels govern the average PM2.5 response to humidity during winter. A decrease of wind speed (keeping constant the emissions) increases all PM2.5 species (on average 40 ng m-3 %-1) due to changes in dispersion and dry deposition. The wind speed effects on sea salt emissions are significant for PM2.5 concentrations over water and in coastal areas. Increases in precipitation have a negative effect on PM2.5 (decreases up to 110 ng m-3 %-1) in all periods due to increases in wet deposition of PM2.5 species and their gas precursors. Changes in mixing height have the smallest effects (up to 35 ng m-3 %-1) on PM2.5. Regarding the relative importance of each of the meteorological parameters

  19. Hormesis for fine particulate matter (PM 2.5).

    PubMed

    Cox, Louis Anthony Tony

    2012-01-01

    The hypothesis of hormesis - that substances that harm health at high exposures can reduce risks below background at low exposures, e.g., if they activate defenses without overwhelming them - becomes important for practical policy making if it holds for regulated substances. Recently, the U.S. EPA concluded that reductions in ambient concentrations of fine particulate matter (PM2.5) in air caused trillions of dollars worth of human health benefits for a compliance cost of only about $65 billion per year. This conclusion depends on an unverified assumption of a positive, causal, straight-line relation between PM2.5 concentrations and mortality risks. We review empirical data on PM2.5 and mortality risks (and their precursors, inflammatory responses) and conclude that the PM2.5 concentration-response relation may be J-shaped, rather than linear. This possibility implies that the 1990 Clean Air Act Amendment may well have produced no (or negative) human health benefits, rather than the trillions of dollars worth of reduced mortalities ascribed to it by EPA; and that attempts to achieve further risk-reduction benefits by further reducing PM2.5 concentrations may be counterproductive. This creates a very high value for scientific information that better reveals the true shape of the PM2.5 concentration-response function at and below current ambient levels. PMID:22740783

  20. Prediction of ambient PM2.5 concentrations in Maryland

    SciTech Connect

    Sherwell, J.; Walsh, K.; Gardner, R.

    1998-12-31

    In 1997 the State of Maryland had no available ambient Federal Reference Method data on particulate matter less than 2.5 microns in aerodynamic diameter (PM2.5) but did have annual ambient data for particulate matter smaller than 10 microns (PM10) at twenty-four sites. The PM10 data was analyzed in conjunction with local annual and seasonal ZIP code-level emission inventories and with speciated PM2.5 data from four nearby monitors in the IMPROVE network (located in the national parks and wilderness areas) in an effort to predict annual average and seasonal high PM2.5 concentrations at the twenty-four PM10 monitor sites operating from 1992 to 1996. All seasonal high concentrations were predicted to be below the 24-hour PM2.5 National Ambient Air Quality Standard (NAAQS) at the sites operating in Maryland between 1992 and 1996. The projections also indicated that twelve monitor sites might exceed the three-year annual average PM2.5 NAAQS of 15 m g/m3, but Maryland`s air quality shows signs that it has been improving since 1992.

  1. Affinity labeling of (2'-5')-oligoadenylate-activated endonuclease with (/sup 32/P)-2', 5'A and its analogs

    SciTech Connect

    Saarma, M.Y.; Gordon, J.; Minks, M.A.

    1985-09-01

    This paper examines the role interferons play in the origin of the antiviral state of cells and in the inhibition of virus reproduction. Treatment of cells with interferon induces the synthesis of a whole series of proteins. For affinity labeling of 2', 5'A-dependent endoribonuclease, the authors synthesized P-32 labeled 2; 5'A by two methods. Results of the investigation show that the most probable candidate for 2', 5'A-dependent endoribonuclease is the protein with molecular weight 80,000. The role of the other two proteins is still unknown.

  2. Personal exposures to PM 2.5 and their relationships with microenvironmental concentrations

    NASA Astrophysics Data System (ADS)

    Lim, Soogil; Kim, Jeonghoon; Kim, Taehyun; Lee, Kiyoung; Yang, Wonho; Jun, Sangil; Yu, Seungdo

    2012-02-01

    Personal exposure to particulate matter of aerodynamic diameters less than 2.5 μm (PM 2.5) can be affected by various factors. The purpose of this study was to determine the impact of activity pattern and the contribution of each microenvironment to personal PM 2.5 exposure. Technicians carried a nephelometer for PM 2.5 while engaging in scripted time location activities. The scripted activities of 10 different population groups were based on time activity patterns of the Seoul population in Korea. A total of 58 daily PM 2.5 personal exposures were available for analysis. The average PM 2.5 personal exposure was 19.8 ± 15.3 μg m -3. The average personal exposure of each population group ranged from 9.8 to 43.1 μg m -3. High peak and average concentrations were observed in restaurants and bars; such high concentrations were due to secondhand smoke and cooking with charcoal on tables. The residential indoor level of the nine microenvironments was the largest contributor to personal exposure. The contributions from residential indoor, non-residential indoor, transportation, and outdoor levels were 36.2%, 53.4%, 6.7%, and 3.7%, respectively. The contributions of microenvironments varied among population groups; these variations suggest that the impact of activity pattern on personal exposure is significant.

  3. Oxidative potential and chemical speciation of size-resolved particulate matter (PM) at near-freeway and urban background sites in the greater Beirut area.

    PubMed

    Daher, Nancy; Saliba, Najat A; Shihadeh, Alan L; Jaafar, Malek; Baalbaki, Rima; Shafer, Martin M; Schauer, James J; Sioutas, Constantinos

    2014-02-01

    To assess particle oxidative potential in the greater Beirut area, size-resolved PM10-2.5, PM2.5-0.25 and PM0.25 samples were collected at near-freeway and urban background sites. Metals and trace elements, including Mn, Cr, Cu, Ba, Mo and Sb, displayed increased levels and crustal enrichment factors at the roadway, indicating their vehicular origin. These elements in addition to Co, V, Ni and Zn were mostly distributed in PM2.5-0.25 and PM0.25 at both sites, with moderate-to-high water-solubility (>30%). The presence of these metals, mainly air toxics, in small size ranges constitutes an added health risk. Of particular concern are elements with strong correlations (R ≥ 0.70) with reactive oxygen species (ROS)-activity, measured by a cellular assay. In PM10-2.5, road dust component Mn and soil-related element Co were highly correlated with ROS-activity. In PM2.5-0.25, vehicular abrasion element Cu and soil-derived component Co were highly associated with ROS-activity. In PM0.25, V and Ni, originating from fuel oil combustion, strongly correlated with ROS formation. ROS-activity displayed a particle-size dependency, with lowest activity associated with PM10-2.5. On a per air volume basis, size-resolved ROS-activity was 1.5-2.8 times greater at the roadside than background location, indicating that exposure to redox-active species may be greatest near the freeway. Size-fractionated PM intrinsic activity (i.e. PM mass-normalized) was comparable at both sites, possibly suggesting a similarity in the sources of ROS-active species. Relative to other urban settings, while the intrinsic redox activity of PM10-2.5 in Beirut is comparable to that measured at an urban site in Los Angeles (LA), its PM0.25-induced ROS-activity is ~2.3-fold greater. Moreover, the intrinsic ROS-activity of ambient PM2.5 in Beirut is comparable to that reported in Milan-Italy, but 3.1-times PM2.5 activity in the heavily-polluted Lahore-Pakistan. Lastly, findings suggest a dominant role of

  4. Greater trochanteric pain syndrome diagnosis and treatment.

    PubMed

    Mallow, Michael; Nazarian, Levon N

    2014-05-01

    Lateral hip pain, or greater trochanteric pain syndrome, is a commonly seen condition; in this article, the relevant anatomy, epidemiology, and evaluation strategies of greater trochanteric pain syndrome are reviewed. Specific attention is focused on imaging of this syndrome and treatment techniques, including ultrasound-guided interventions. PMID:24787333

  5. BLOCKAGE 2.5 user`s manual

    SciTech Connect

    Rao, D.V.; Brideau, J.; Shaffer, C.; Souto, F.; Bernahl, W.

    1996-12-01

    The BLOCKAGE 2.5 code described in this User`s Manual was developed by the US Nuclear Regulatory Commission (NRC) as a tool to evaluate licensee compliance with NRC Bulletin 96-03, ``Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in Boiling Water Reactors.`` As such, BLOCKAGE 2.5 provides a generalized framework into which a user can input plant-specific and insulation-specific data for performing analyses in accordance with Regulatory Guide 1.82, Rev. 2. This user`s manual describes the capabilities of BLOCKAGE 2.5 along with a description of the graphics user`s interface provided for data entry. Each input/output dialog is described in detail along with special considerations related to developing and executing BLOCKAGE. Also, several sample problems are provided such that user can easily modify them to suit a particular plant of interest. The models used in BLOCKAGE 2.5 and their validation are presented in the accompanying NUREG/CR-6371. The BLOCKAGE models were designed to be parametric in nature, allowing the user flexibility to examine the impact of several modeling assumptions and to conduct sensitivity analyses. As a result, BLOCKAGE 2.5 results are known to be very sensitive to the user provided input. It is therefore strongly recommended that users become thoroughly familiar with BLOCKAGE models and their limitations as described in NUREG/CR-6224.

  6. PM2.5 monitoring network design strategies

    SciTech Connect

    DuBois, D.W.; Watson, J.G.; Chow, J.C.; Green, M.; Frank, N.; Pitchford, M.

    1998-12-31

    In response to the US EPA National Ambient Air Quality Standards for PM2.5, a new network of PM2.5 monitors will be required throughout the nation. The PM2.5 monitoring network will represent population or community exposure where people live, work and play. These do not necessarily correspond to the locations of maximum concentrations in an area. The network of PM2.5 monitors will likely approach 1,500 in number as the implementation gets underway. PM2.5 monitors are to be located at specific sites that represent neighborhood or urban scales to determine compliance with standards. Transport and background sites are located between, and away from, planning areas to determine regional increments to PM measured around the planning area. Network design philosophies examined in this paper include random, systematic, judgmental sampling, combined judgmental/systematic sampling and other analytical model based sampling techniques. Methods to determine the information content of different monitors were also evaluated.

  7. The effects of marine vessel fuel sulfur regulations on ambient PM2.5 along the west coast of the U.S.

    NASA Astrophysics Data System (ADS)

    Kotchenruther, Robert A.

    2015-02-01

    This work uses PM2.5 data and Positive Matrix Factorization (PMF) modeling to explore the effects of two marine vessel fuel sulfur regulations along the west coast of the United States (US); California's (CA) Ocean-Going Vessel Clean Fuel Regulation (CA-CFR) implemented in July 2009 and the North American Emissions Control Area (NA-ECA) implemented in August 2012. Data from 31 chemically speciated PM2.5 monitors along the US west coast were analyzed and 9 sites with strong linear correlations between vanadium and nickel were selected for PMF modeling. The 9 sites were modeled independently and for 8 sites, 3 in CA and 5 in Washington State (WA), a well-defined factor linked to marine vessel residual fuel oil (RFO) combustion was identified. For these 8 sites, model results were subdivided into three time periods; a three year period prior to implementation of the CA-CFR, a three year period after the CA-CFR but prior to the NA-ECA, and a one year period after implementation of the NA-ECA. Marine vessel PM2.5 distributions were compared between the three time periods to determine if statistically significant reductions had occurred. Comparing marine vessel PM2.5 for the three years before and after CA-CFR implementation, all CA sites indicated statistically significant reductions, with reductions in annualized average marine vessel PM2.5 from 30 to 52% (0.09-0.78 μg/m3). Comparing marine vessel PM2.5 for the three years before NA-ECA implementation and the 1 year after, 2 of 5 WA sites indicated statistically significant reductions in annualized average impacts (45-50%, 0.12-0.23 μg/m3) and 1 of 3 sites in CA (46%, 0.04 μg/m3). These results demonstrate that marine vessel fuel sulfur regulations on the west coast of the US have been effective at reducing PM2.5 impacts from marine vessel RFO combustion at some locations, with the implementation of the CA-CFR showing more success than the NA-ECA. The greater observed success of the CA-CFR is, to some extent

  8. Portable Life Support System 2.5 Fan Design and Development

    NASA Technical Reports Server (NTRS)

    Quinn, Gregory; Carra, Michael; Converse, David; Chullen, Cinda

    2016-01-01

    NASA is building a high-fidelity prototype of an advanced Portable Life Support System (PLSS) as part of the Advanced Exploration Systems Program. This new PLSS, designated as PLSS 2.5, will advance component technologies and systems knowledge to inform a future flight program. The oxygen ventilation loop of its predecessor, PLSS 2.0, was driven by a centrifugal fan developed using specifications from the Constellation Program. PLSS technology and system parameters have matured to the point where the existing fan will not perform adequately for the new prototype. In addition, areas of potential improvement were identified with the PLSS 2.0 fan that could be addressed in a new design. As a result, a new fan was designed and tested for the PLSS 2.5. The PLSS 2.5 fan is a derivative of the one used in PLSS 2.0, and it uses the same nonmetallic, canned motor, with a larger volute and impeller to meet the higher pressure drop requirements of the PLSS 2.5 ventilation loop. The larger impeller allows it to operate at rotational speeds that are matched to rolling element bearings, and which create reasonably low impeller tip speeds consistent with prior, oxygen-rated fans. Development of the fan also considered a shrouded impeller design that could allow larger clearances for greater oxygen safety, assembly tolerances and particle ingestion. This paper discusses the design, manufacturing and performance testing of the new fans.

  9. AMBIENT PM2.5 SAMPLING AND ANALYSIS

    SciTech Connect

    Unknown

    2001-10-31

    This interim report summarizes detailed findings and conclusions drawn from evaluations of data obtained from the operation of ambient PM{sub 2.5} speciation sites in a geographical area encompassing southeastern Ohio, western Pennsylvania and northwestern West Virginia. The overall goal of this program, called the Upper Ohio River Valley Project (UORVP), is to better understand the relationship between coal-based power system emissions and ambient air quality in the Upper Ohio River Valley region through the collection of chemically resolved or speciated data. A summary of the sampling activities, sample analyses and the correlation and interpretation of data acquired from February 1999 through March of 2001 are reported. Mass and speciated data from urban and rural sources are compared and seasonal variations in PM{sub 2.5} distribution are also examined. Correlations between meteorological parameters and total PM{sub 2.5} mass are also presented.

  10. AMBIENT PM2.5 SAMPLING AND ANALYSIS

    SciTech Connect

    Unknown

    2002-10-31

    This interim report summarizes detailed findings and conclusions drawn from evaluations of data obtained from the operation of ambient PM{sub 2.5} speciation sites in a geographical area encompassing southeastern Ohio, western Pennsylvania and northwestern West Virginia. The overall goal of this program, called the Upper Ohio River Valley Project (UORVP), is to better understand the relationship between coal-based power system emissions and ambient air quality in the Upper Ohio River Valley region through the collection of chemically resolved or speciated data. A summary of the sampling activities, sample analyses and the correlation and interpretation of data acquired from February 1999 through March of 2001 are reported. Mass and speciated data from urban and rural sources are compared and seasonal variations in PM{sub 2.5} distribution are also examined. Correlations between meteorological parameters and total PM{sub 2.5} mass are also presented.

  11. Study on ambient concentrations of PM 10, PM 10-2.5, PM 2.5 and gaseous pollutants. Trace elements and chemical speciation of atmospheric particulates

    NASA Astrophysics Data System (ADS)

    Dongarrà, G.; Manno, E.; Varrica, D.; Lombardo, M.; Vultaggio, M.

    2010-12-01

    This study provides the first comprehensive report on mass concentrations of particulate matter of various sizes, inorganic and organic gas concentrations monitored at three sampling sites in the city of Palermo (Sicily, Italy). It also provides information on the water-soluble species and trace elements. A total of 2054 PM 10 (1333) and PM 2.5 (721) daily measurements were collected from November 2006 to February 2008. The highest mass concentrations were observed at the urban stations, average values being about two times higher than those at the suburban (control) site. Time variations in PM 10 and also PM 10-2.5 were observed at the urban stations, the highest concentrations being measured in autumn and winter. CO, NOx, NO 2, benzene, toluene and o-xylene concentrations peaked in autumn and winter, a pattern similar to those recorded for PM 10 and PM 10-2.5 mass levels, indicating the importance of traffic emissions in urban air pollution. 91% and 51% of the benzene measurements exceeded the limit of 5 μg m -3 at the two urban monitoring sites. Trace elements (As, Ba, Cr, Cu, Mo, Pb, Sb) suspected of being introduced into the atmosphere mainly by anthropogenic activities, were highly enriched with respect to local soil. Results indicate that a large fraction of PM 10 (31-47% in weight) and PM 2.5 (29% in weight) is made up of water-soluble ions. Ammonium sulphate and nitrate particles accounted for 14-29 wt% of particulate matter mass concentrations. Crustal and marine components, combined, account for 41% and 49% in PM 2.5 and PM 10, respectively. The calculated deficits in Cl - and NH 4+ ions suggest that a proportion of these ions are lost, via the formation of gaseous NH 4Cl or HCl and NH 3.

  12. 2.5D dictionary learning based computed tomography reconstruction

    NASA Astrophysics Data System (ADS)

    Luo, Jiajia; Eri, Haneda; Can, Ali; Ramani, Sathish; Fu, Lin; De Man, Bruno

    2016-05-01

    A computationally efficient 2.5D dictionary learning (DL) algorithm is proposed and implemented in the model- based iterative reconstruction (MBIR) framework for low-dose CT reconstruction. MBIR is based on the minimization of a cost function containing data-fitting and regularization terms to control the trade-off between data-fidelity and image noise. Due to the strong denoising performance of DL, it has previously been considered as a regularizer in MBIR, and both 2D and 3D DL implementations are possible. Compared to the 2D case, 3D DL keeps more spatial information and generates images with better quality although it requires more computation. We propose a novel 2.5D DL scheme, which leverages the computational advantage of 2D-DL, while attempting to maintain reconstruction quality similar to 3D-DL. We demonstrate the effectiveness of this new 2.5D DL scheme for MBIR in low-dose CT. By applying the 2D DL method in three different orthogonal planes and calculating the sparse coefficients accordingly, much of the 3D spatial information can be preserved without incurring the computational penalty of the 3D DL method. For performance evaluation, we use baggage phantoms with different number of projection views. In order to quantitatively compare the performance of different algorithms, we use PSNR, SSIM and region based standard deviation to measure the noise level, and use the edge response to calculate the resolution. Experimental results with full view datasets show that the different DL based algorithms have similar performance and 2.5D DL has the best resolution. Results with sparse view datasets show that 2.5D DL outperforms both 2D and 3D DL in terms of noise reduction. We also compare the computational costs, and 2.5D DL shows strong advantage over 3D DL in both full-view and sparse-view cases.

  13. PM2.5 speciation -- objectives, requirements, and approach

    SciTech Connect

    Homolya, J.B.; Rice, J.; Scheffe, R.D.

    1998-12-31

    Chemical speciation of selected PM2.5 monitor samples is included in the discussion of major monitoring requirements and principles described in the Part 58 Rule. The regulation requires the implementation of a modest chemical speciation network of 50 PM2.5 sites that provides a first order characterization of the metals, ions, and carbon constituents of PM2.5. These data are to be used to support several areas of interest, including: (1) Helping to implement the PM2.5 standard through the use of speciated data as inputs to air quality modeling analyses and as indicators to track progress of controls; (2) Aiding the interpretation of health studies by linking effects to PM2.5 constituents; (3) Understanding the effects of atmospheric constituents on visibility impairment; and (4) Using speciated particulate data to aid in monitoring network design and siting adjustment. For these reasons, EPA has developed plans for the initial 50-site speciation monitoring network that include collocating at least 25 monitors within the Photochemical Air Monitoring System (PAMS) which collect data for a range of volatile hazardous air pollutants and ozone. Therefore these initial speciation sites will provide EPA and the research community a baseline of gaseous and particulate atmospheric characterization information. Current plans include the outfitting of up to 300 PM2.5 speciation monitoring sites. The speciation monitors are currently being fabricated under EPA National Federal Reference Method monitor procurement contracts and are projected to begin to be deployed in 10/98. This paper will present a detailed discussion of the design and implementation of the speciation monitoring network and explain EPA`s approach to implementation of the monitoring activities which includes siting, target analytes of interest, sample handling, analytical SOPs, and data reduction, validation and reporting.

  14. Chemical PM2.5 Speciation in Major Cities Worldwide

    NASA Astrophysics Data System (ADS)

    Snider, Graydon; Weagle, Crystal; Brauer, Michael; Cohen, Aaron; Gibson, Mark; Liu, Yang; Martins, Vanderlei; Rudich, Yinon; Martin, Randall

    2016-04-01

    We examined the chemical composition of fine particulate matter (PM2.5) across 13 globally dispersed urban locations (including Atlanta, Buenos Aires, Beijing, Manila, and Dhaka), as part of the Surface PARTiculate mAtter Network (SPARTAN). At each site sampling was conducted over 4 to 24 months for the years 2013 to 2015. Analysis of filter samples revealed that several PM2.5 chemical components varied by more than an order of magnitude between sites. Ammonium sulfate ranged from 2 μg m‑3 (Ilorin) to 17 μg m‑3 (Kanpur). Ammonium nitrate ranged from 0.2 μg m‑3 (Atlanta) to 6.7 μg m‑3 (Kanpur). Effective black carbon ranged from 0.4 μg m‑3 (Atlanta) to 5 μg m‑3 (Dhaka and Kanpur). The all-site mean values of major PM2.5 constituents were ammonium sulfate (20 ± 10 %), crustal material (12 ± 6.5%), effective black carbon (10 ± 7.4 %), ammonium nitrate (3.7 ± 2.5%), sea salt (2.2 ± 1.5%), trace element oxides (0.9 ± 0.7 %), water (7.2 ± 3.0%) and residue materials (44 ± 24%). Based on the evaluation with collocated studies we treated residue material as mostly organic. Major ions generally agreed well with previous studies at the same urban locations (e.g. sulfate fractions agreed within 4% for eight out of 11 collocation comparisons). Enhanced crustal material (CM) concentrations with high Zn:Al ratios at large cities (e.g. Hanoi, Dhaka, Manila) imply significant anthropogenic CM contributions that deserve more attention. Detailed chemical speciation also aided our characterization of site-specific PM2.5 water retention. The expected water contribution to aerosols was calculated via the hygroscopicity parameter for each filter. Hourly PM2.5 at specified relative humidity (35%) was inferred from nephelometer measurements of light scatter at ambient relative humidity and 9-day filter measurements of PM2.5 mass. Our PM2.5 estimates compared favorably with a beta attenuation monitor (BAM) at the nearby US embassy in Beijing, with a coefficient of

  15. Correlation between microstructure and charge transport in poly(2,5-dimethoxy- p -phenylenevinylene) thin films

    NASA Astrophysics Data System (ADS)

    Sims, M.; Tuladhar, S. M.; Nelson, J.; Maher, R. C.; Campoy-Quiles, M.; Choulis, S. A.; Mairy, M.; Bradley, D. D. C.; Etchegoin, P. G.; Tregidgo, C.; Suhling, K.; Richards, D. R.; Massiot, P.; Nielsen, C. B.; Steinke, J. H. G.

    2007-11-01

    We report a study of thin films of poly(2,5-dimethoxy- p -phenylenevinylene) (PDMeOPV) prepared by a precursor route. Conversion at two different temperatures, namely, 120 and 185°C , produces partially and fully converted films. We study the structural, optical, and charge transport characteristics of these samples in order to relate transport properties to microstructure. Micro-Raman mapping and photoluminescence (PL) imaging reveal the existence of coarse, depth-averaged domains of around 50μm in lateral extent, with more pronounced contrast for conversion at the higher temperature. The contrast in both micro-Raman and PL maps can be attributed to fluctuations in film density. Spectroscopic ellipsometry studies of the films indicate that the average film density is approximately 15% higher for conversion at the higher temperature. Time-of-flight photocurrent transients, recorded here in PDMeOPV films, are typically dispersive but yield hole mobilities in excess of 10-4cm2/Vs at modest applied fields (˜1.2×105V/cm) in the fully converted films. To our knowledge, these are amongst the highest reported mobility values for a poly( p -phenylenevinylene) derivative. Fully converted films, while yielding higher hole mobilities, exhibit a stronger dependence on electric field than partially converted ones. The higher mobility can be attributed to the almost complete conversion of the flexible saturated subunits within precursor chains to conjugated vinylene moieties at elevated temperature. This results in a correspondingly higher packing density, an improvement in intrachain transport, and a reduction in the smallest interchain hopping distance. We suggest that the stronger electric field dependence is due to the increasing influence of intermolecular electrostatic interactions with decreasing interchain separation. We propose that a greater proportion of chains in the fully converted films packs in a three-dimensional, interdigitated arrangement similar to that

  16. 2-5A ligands--a new concept for the treatment of prostate cancer.

    PubMed

    Cramer, Hagen; Okicki, James R; Rho, Taikyun; Wang, Xinning; Silverman, Robert H; Heston, Warren D W

    2007-01-01

    Several potent prostate specific membrane antigen (PSMA) inhibitors have been described recently. We generated a PSMA-specific 2-5A ligand called RBI 1033 by linking 2-5A to the N-acetylaspartylglutamate (NAAG)-based inhibitor ZJ-24. We measured the inhibitory activity of RBI 1033 to the folate hydrolase activity of PSMA. Amazingly, we found that compared to ZJ-24 (IC50 = 53.9 nM), RBI 1033 was more than 10 times more potent (IC50 = 4.78 nM) as a folate hydrolase inhibitor, while SMCC 2-5A lacking the ZJ-24 part, did not show much activity (IC50 = 1974 nM). Also, RBI 1033's affinity to PSMA was found to be 10 times higher than ZJ-24 itself. PMID:18066809

  17. Extending Interactive Writing into Grades 2-5

    ERIC Educational Resources Information Center

    Roth, Kate; Dabrowski, Joan

    2014-01-01

    Interactive writing is an instructional practice widely considered effective and most appropriate for emergent writers. This article asserts that it is a valuable method for more fluent writers in grades 2-5. It outlines the basic lesson sequence and proposes four key shifts to adapt interactive writing for older, more fluent writers: 1) The…

  18. Science in Action Series: AGATE (pt 2/5 )

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This show was made for the Office of Education at NASA Langley. The objective is to make math and science appealing to a middle school audience. This clip (pt 2/5 ) is an animation which tells us a little about the plane itself: including capacity, speed and range.

  19. 43 CFR 3472.2-5 - Special qualifications, public bodies.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Special qualifications, public bodies... PROVISIONS AND LIMITATIONS Lease Qualification Requirements § 3472.2-5 Special qualifications, public bodies... public body shall submit: (1) Evidence of the manner in which it is organized; (2) Evidence that it...

  20. 75 FR 14259 - Transportation Conformity Rule PM2.5

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-24

    .... EPA first promulgated the transportation conformity rule on November 24, 1993 (58 FR 62188), and... a final rule EPA published on July 1, 2004 (69 FR 40004), EPA provided conformity procedures for... Precursors'' (70 FR 24280). This final rule specified transportation-related PM 2.5 precursors and when...

  1. SITE CHARACTERIZATION LIBRARY: VOLUMN 1 (RELEASE 2.5)

    EPA Science Inventory

    This CD-ROM, Volume 1, Release 2.5, of EPA's National Exposure Research Laboratory (NERL - Las Vegas) Site Characterization Library, contains additional electronic documents and computer programs related to the characterization of hazardous waste sites. EPA has produced this libr...

  2. Source apportionment of PM2.5 in Seoul, Korea

    NASA Astrophysics Data System (ADS)

    Heo, J.-B.; Hopke, P. K.; Yi, S.-M.

    2009-07-01

    PM2.5 samples were collected at a centrally located urban monitoring site in Seoul, Korea, every third day from March 2003 to December 2006 and analyzed for their chemical constituents. Sources were identified using positive matrix factorization (PMF). A total of 393 samples were obtained during the sampling period, and 20 chemical species were measured. Nine PM2.5 source categories were identified providing physically realistic profiles and interesting insights into the source contributions to the ambient mass concentrations. The major contributors of PM2.5 were secondary nitrate (20.9%), secondary sulfate (20.5%), gasoline-fueled vehicles (17.2%), and biomass burning (12.1%), with lesser contributions from diesel emissions (8.1%), soil (7.4%), industry (6.7%), road salt and two-stroke vehicles (5.1%), and aged sea salt (2.2%). PM2.5 levels in Seoul were influenced by both local urban activities and regional-scale transport. Conditional probability function (CPF) results identified possible source directions of local sources such as motor vehicles (gasoline and diesel), industry, and road salt. Potential source contribution function (PSCF) results showed that possible source areas contributing to the elevated secondary particle concentrations (sulfate and nitrate) in Seoul to be the major industrial areas in China.

  3. Source apportionment of PM2.5 in Seoul, Korea

    NASA Astrophysics Data System (ADS)

    Heo, J.-B.; Hopke, P. K.; Yi, S.-M.

    2008-12-01

    PM2.5 samples were collected at a centrally located urban monitoring site in Seoul, Korea, every third day from March 2003 to December 2006 and analyzed for their chemical constituents. Sources were identified using Positive Matrix Factorization (PMF). A total of 393 samples were obtained during the sampling period, and 20 chemical species were measured. Nine PM2.5 sources were identified providing physically realistic profiles and interesting insights into the source contributions to the ambient mass concentrations. The major sources of PM2.5 were secondary nitrate (20%), secondary sulfate (20%), gasoline-fueled vehicles (17%), and biomass burning (12%), with lesser contributions from diesel emissions (8%), soil (7%), industry (6%), road salt and two-stroke engine (5%), and aged sea salt (2%). PM2.5 levels in Seoul were influenced by both local urban activities and regional-scale transport. Conditional Probability Function (CPF) results identified possible source directions of local sources such as motor vehicles (gasoline and diesel), industry, and road salt. Potential Source Contribution Function (PSCF) results showed that possible source areas contributing to the elevated secondary particle concentrations (sulfate and nitrate) in Seoul to be the major industrial areas in China.

  4. 2,5-hexanedione-induced immunomodulatory effect in mice

    SciTech Connect

    Upreti, R.K.; Shanker, R.

    1987-06-01

    The immunotoxic potential of 2,5-hexanedione (2,5-Hxdn), the end metabolite of n-hexane/methyl n-butyl ketone, was evaluated in a mouse model involving multiple pathomorphological, hematological, and immunological assays. Young adult male Swiss albino mice were given either single or seven consecutive oral doses of 0.2 x LD/sub 50/ of 2.5-Hxdn. None of the treated mice exhibited any sign of hind limb weakness up to 1 week. On the eighth day, half the animals were sacrificed for initial pathomorphological studies of various organs and the other half were subjected to several immune function tests. The results revealed treatment-related reduction in cellularity of spleen, thymus, and mesentric lymph nodes and pathotoxicological changes. Further, immune function tests such as delayed-type hypersensitivity reaction, plaque-forming cell assay, phagocytosis by adherent peritoneal exudate cells, and resistance to endotoxin shock were considerably impaired. These results suggest that 2,5-Hxdn treatment causes profound impairment of immunity in mice even before the onset of peripheral neuropathy.

  5. 11 CFR 2.5 - Procedures for closing meetings.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... each item on an agenda proposed to be closed in whole or in part pursuant to 11 CFR 2.4, or with... close that portion to the public for any of the reasons referred to in 11 CFR 2.4. The following... procedures for closing a meeting set forth in 11 CFR 2.5 (a) through (d)....

  6. 11 CFR 2.5 - Procedures for closing meetings.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... each item on an agenda proposed to be closed in whole or in part pursuant to 11 CFR 2.4, or with... close that portion to the public for any of the reasons referred to in 11 CFR 2.4. The following... procedures for closing a meeting set forth in 11 CFR 2.5 (a) through (d)....

  7. Upper Body Muscular Endurance Among Children 2-5 Years.

    ERIC Educational Resources Information Center

    Gabbard, Carl P.; And Others

    The upper body muscular endurance of males and females 2-5 years of age was assessed, and relationships relative to sex, age, endurance and selected anthropometric measures were investigated. None of the relationships were found to be of practical predicative value; while upper body muscular strength increased with age, no significant differences…

  8. PM 2.5 Airborne Particulates Near Frac Sand Operations.

    PubMed

    Walters, Kristin; Jacobson, Jeron; Kroening, Zachary; Pierce, Crispin

    2015-11-01

    The rapid growth of hydraulic fracturing for oil and gas extraction in the U.S. has led to 135 active "frac" sand mines, processing plants, and rail transfer stations in Wisconsin. Potential environmental health risks include increased truck traffic, noise, ecosystem loss, and groundwater, light, and air pollution. Emitted air contaminants include fine particulate matter (PM2.5) and respirable crystalline silica. Inhalation of fine dust particles causes increased mortality, cardiovascular disease, lung disease, and lung cancer. In the authors' pilot study, use of a filter-based ambient particulate monitor found PM2.5 levels of 5.82-50.8 µg/m3 in six 24-hour samples around frac sand mines and processing sites. Enforcement of the existing U.S. Environmental Protection Agency annual PM2.5 standard of 12 µg/m3 is likely to protect the public from silica exposure risks as well. PM2.5 monitoring around frac sand sites is needed to ensure regulatory compliance, inform nearby communities, and protect public health. PMID:26638669

  9. Men Face Greater Risk of Cardiac Arrest

    MedlinePlus

    ... nlm.nih.gov/medlineplus/news/fullstory_159651.html Men Face Greater Risk of Cardiac Arrest: Study Heart ... 30, 2016 THURSDAY, June 30, 2016 (HealthDay News) -- Men are significantly more likely to have their heart ...

  10. Men Face Greater Risk of Cardiac Arrest

    MedlinePlus

    ... fullstory_159651.html Men Face Greater Risk of Cardiac Arrest: Study Heart disease tends to develop earlier than ... About one in nine men will suffer a cardiac arrest before the age of 70, compared to about ...

  11. Chemical Characterization of Outdoor and Subway Fine (PM2.5–1.0) and Coarse (PM10–2.5) Particulate Matter in Seoul (Korea) by Computer-Controlled Scanning Electron Microscopy (CCSEM)

    PubMed Central

    Byeon, Sang-Hoon; Willis, Robert; Peters, Thomas M.

    2015-01-01

    Outdoor and indoor (subway) samples were collected by passive sampling in urban Seoul (Korea) and analyzed with computer-controlled scanning electron microscopy coupled with energy dispersive x-ray spectroscopy (CCSEM-EDX). Soil/road dust particles accounted for 42%–60% (by weight) of fine particulate matter larger than 1 µm (PM2.5–1.0) in outdoor samples and 18% of PM2.5–1.0 in subway samples. Iron-containing particles accounted for only 3%–6% in outdoor samples but 69% in subway samples. Qualitatively similar results were found for coarse particulate matter (PM10–2.5) with soil/road dust particles dominating outdoor samples (66%–83%) and iron-containing particles contributing most to subway PM10–2.5 (44%). As expected, soil/road dust particles comprised a greater mass fraction of PM10–2.5 than PM2.5–1.0. Also as expected, the mass fraction of iron-containing particles was substantially less in PM10–2.5 than in PM2.5–1.0. Results of this study are consistent with known emission sources in the area and with previous studies, which showed high concentrations of iron-containing particles in the subway compared to outdoor sites. Thus, passive sampling with CCSEM-EDX offers an inexpensive means to assess PM2.5–1.0 and PM10-2.5 simultaneously and by composition at multiple locations. PMID:25689348

  12. /sup 125/I)-(d(CH2)5, Sar7)AVP: a selective radioligand for V1 vasopressin receptors

    SciTech Connect

    Kelly, J.M.; Abrahams, J.M.; Phillips, P.A.; Mendelsohn, F.A.; Grzonka, Z.; Johnston, C.I.

    1989-01-01

    Arginine8-vasopressin (AVP) acts on vascular and hepatic V1 receptors to influence blood pressure and glycogenolysis respectively. We have radioiodinated the AVP V1 receptor antagonist, (1-(beta-mercapto-beta, beta-cyclopentamethylenepropionic-acid), 7-sarcosine, 8-arginine) vasopressin ((d(CH2)5, Sar7)AVP) and determined its receptor-binding properties in rat liver and kidney plasma membranes. The binding was of high affinity to single classes of receptors (liver: Kd = 3.0 nM and Bmax = 530 +/- 10 fmol/mg protein, kidney: Kd = 0.5 +/- 0.9 nM and Bmax = 11 +/- 8 fmol/mg protein). Competition of (125I)-(d(CH2)5, Sar7)AVP binding by unlabelled AVP analogues gave the following order of potency in both tissues, consistent with that expected for binding to a V1 receptor: (d(CH2)5, Tyr(Me)2)AVP greater than AVP greater than (d(CH2)5, D-Ile2, Ile4) AVP greater than DDAVP. No degradation of (125I)-(d(CH2)5, Sar7)AVP during incubation or storage was detected by HPLC analysis. We have used (125I)-(d(CH2)5, Sar7)AVP and in vitro autoradiography to demonstrate its use in localizing brain AVP receptors. These studies suggest that (125I)-(d(CH2)5, Sar7)AVP is a suitable selective radioligand for labelling V1 receptors and will provide a valuable tool for the study of the localization and regulation of AVP V1 receptors in tissues and in receptor isolation.

  13. Spatial and temporal variability of ultrafine particles, NO2, PM2.5, PM2.5 absorbance, PM10 and PMcoarse in Swiss study areas

    NASA Astrophysics Data System (ADS)

    Eeftens, Marloes; Phuleria, Harish C.; Meier, Reto; Aguilera, Inmaculada; Corradi, Elisabetta; Davey, Mark; Ducret-Stich, Regina; Fierz, Martin; Gehrig, Robert; Ineichen, Alex; Keidel, Dirk; Probst-Hensch, Nicole; Ragettli, Martina S.; Schindler, Christian; Künzli, Nino; Tsai, Ming-Yi

    2015-06-01

    Exposure to outdoor air pollutants remains an important concern in Europe, as limit values for NO2 and PM10 continue to be exceeded. Few studies have addressed the long-term spatial contrasts in PM2.5, PM absorbance, PMcoarse and especially ultrafine particles. This scarcity of data hampers the possibility to conduct epidemiological studies, assessing the health relevance of these markers of potentially harmful pollutants. Air pollution measurements were performed in eight geographically distinct areas of the Swiss Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA) in Switzerland. NO2 was measured in all eight areas at 40 sites per area, and PM2.5, PM2.5 absorbance, PM10 and ultrafine particles (particle number concentration (PNC) and lung deposited surface area (LDSA)) were measured in 4 of these areas, at a subset of 20 out of 40 sites. Each site was sampled three times during different seasons of the year, using the same equipment, sampling protocols and the same central facilities for analysis of samples. We assessed the spatial variability between areas and between individual sites, as well as pollution contrasts between the seasons and correlations between different pollutants. Within-area spatial contrasts (defined as the ratio between the 90th and 10th percentile) were highest for NO2 (3.14), moderate for PMcoarse (2.19), PNC (2.00) and PM2.5 absorbance (1.94), and lowest for LDSA (1.63), PM2.5 (1.50) and PM10 (1.46). Concentrations in the larger cities were generally higher than in smaller towns and rural and alpine areas, and were higher in the winter than in the summer and intermediate seasons, for all pollutants. Between-area differences accounted for more variation than within-area differences for all pollutants except NO2 and PMcoarse. Despite substantial within-area contrasts for PNC and LDSA, 74.7% and 83.3% of the spatial variance was attributed to between-area variability, respectively. Coefficients of determination between

  14. Genotoxicity biomarkers for airborne particulate matter (PM2.5) in an area under petrochemical influence.

    PubMed

    Lemos, Andréia Torres; Lemos, Clarice Torres de; Flores, Andressa Negreiros; Pantoja, Eduarda Ozório; Rocha, Jocelita Aparecida Vaz; Vargas, Vera Maria Ferrão

    2016-09-01

    The effects of fine inhalable particles (PM2.5) were evaluated in an area under the influence of a petrochemical industry, investigating the sensitivity of different genotoxicity biomarkers. Organic extracts were obtained from PM2.5 samples at two sites, positioned in the first and second preferential wind direction in the area. The extracts were evaluated with Salmonella/microsome assay, microsuspension method, strains TA98, YG1021 and YG1024. The mammalian metabolization fraction (S9) was used to evaluate metabolite mutagenicity. The Comet Assay (CA) and Micronuclei Test were used in a Chinese hamster lung cell line (V79). All extracts showed mutagenicity in Salmonella, and nitrogenated compounds were strongly present. Genotoxicity were found in CA in almost all extracts and the micronuclei induction at the Site in the first (Autumn 1, Winter 1), and in the second (Spring 2) wind direction. V79 showed cytotoxicity in all samples. The three biomarkers were concordant in characterization Site NO with worse quality, compatible with the greater pollutants dispersion in the first wind direction. All PM2.5 concentrations were lower than those recommended by air quality standards but genotoxic effects were detected in all samples, corroborating that these standards are inadequate as quality indicators. The Salmonella/microsome assay proved sensitive to PM2.5 mutagenicity, with an outstanding influence of nitroarenes and aromatic amines. Analyses using CA and the micronucleus test broadened the levels of response that involve different damage induction mechanisms. Results show that the complex PM2.5 composition can provoke various genotoxic effects and the use of different bioassays is essential to understand its effects. PMID:27343868

  15. DEVELOPMENT AND EVALUATION OF A CONTINUOUS COARSE (PM10-PM2.5) PARTICLE MONITOR

    EPA Science Inventory

    In this paper, we describe the development and laboratory and field evaluation of a continuous coarse (2.5-10 um) particle mass (PM) monitor that can provide reliable measurements of the coarse mass (CM) concentrations in time intervals as short as 5-10 min. The operating princ...

  16. Air Pollution Exposure Model for Individuals (EMI) in Health Studies: Evaluation for Ambient PM2.5

    EPA Science Inventory

    Health studies of fine particulate matter (PM2.5) often use outdoor concentrations as exposure surrogates, which fail to account for indoor attenuation of ambient PM2.5 and time indoors. To address these limitations, we developed an air pollution exposure model for individuals (E...

  17. [Estimation of PM2.5 Concentration over the Yangtze Delta Using Remote Sensing: Analysis of Spatial and Temporal Variations].

    PubMed

    Xu, Jian-hui; Jiang, Hong

    2015-09-01

    Satellite remote sensing retrieved aerosol optical thickness is widely used to monitor surface PM2.5 concentration. In order to monitor PM2.5 by remote sensing in the Yangtze delta, estimate model of PM2.5 concentration was constructed based on MODIS AOT, PM2.5 concentration data of the 36 ground air quality observation sites and meteorological data in 2013. Afterwards, the model estimated PM2.5 was validated by PM2.5 concentration data from the 17 ground air quality observation sites, and the results showed that the model estimation was higher. The correlation coefficient value of R2 between model estimation of PM2.5 concentration and the value of the ground monitoring of spring, summer, autumn and winter were 0. 45, 0. 50, 0. 58 and 0. 52, respectively. The variation characteristics of temporal and spatial was analyzed based on the long time PM2.5 data together with model estimated, and an increase trend of PM2.5 concentration was observed from 2000 to 2013, with the maximum concentration of PM2.5 (66. 2 µg.m-3 ± 19. 3 µg.m-3) in February and minimum in December (22.6 µg.m-3 ± 5. 9 µg.m-3). In addition, it was found that the distribution of PM2.5 concentration was of obvious features, displaying high value in south and low in north. Mass concentration of PM2.5 was peaked in the zone of urban agglomeration which was grouped to a delta-shaped region by Shanghai, Hangzhou and Nanjing, while the low value areas were in the forest away from city. The result suggested that MODIS AOT and meteorological data can be used to monitor regional PM2.5 by the established multi-linear regression model. PMID:26717669

  18. Chitosan derivatives cross-linked with iodinated 2,5-dimethoxy-2,5-dihydrofuran for non-invasive imaging.

    PubMed

    Ghosh, Paulomi; Das, Manisit; Rameshbabu, Arun Prabhu; Das, Dipankar; Datta, Sayanti; Pal, Sagar; Panda, Asit Baran; Dhara, Santanu

    2014-10-22

    Radiopaque polymer derivatives were successfully prepared through surface diffusion mediated cross-linking of chitosan with iodinated 2,5-dimethoxy-2,5-dihydrofuran. The incorporation of iodine in 2,5-dimethoxy-2,5-dihydrofuran was validated by (1)H NMR and mass spectroscopy. The cross-linking of the glucosamine moieties of chitosan with the iodinated product was confirmed by (13)C NMR and energy-dispersive X-ray spectroscopy. Radiography analysis proved inherent opacity of the iodinated fibrous sheets and microspheres that were comparable to the X-ray visibility of aluminum hollow rings of equivalent thickness and commercially available radiopaque tape, respectively. Microscopic studies evidenced retention of the fiber/microsphere morphology after the iodination/cross-linking reactions. The effects of iodination/cross-linking on the mechanical and biodegradation properties of fibers were studied by nanoindentation and enzymatic assay, respectively. In vitro and in vivo studies established the nontoxic, biodegradable nature of radiopaque derivatives. Iodinated fiber mesh implanted in a rabbit model was significantly X-ray opaque compared to the uncross-linked fiber mesh and medical grade surgical swabs. Further, opacity of the iodinated mesh was evident even after 60 days, though the intensity was reduced, which indicates the biodegradable nature of the iodinated polymer. The opacity of the iodinated sutures was also established in the computed tomography images. Finally, the sufficient in vivo contrast property of the radiopaque microspheres in the gastrointestinal tract indicates its possible role in clinical diagnostics. PMID:25265599

  19. The modifying effect of the building envelope on population exposure to PM2.5 from outdoor sources

    PubMed Central

    Taylor, J; Shrubsole, C; Davies, M; Biddulph, P; Das, P; Hamilton, I; Vardoulakis, S; Mavrogianni, A; Jones, B; Oikonomou, E

    2014-01-01

    A number of studies have estimated population exposure to PM2.5 by examining modeled or measured outdoor PM2.5 levels. However, few have taken into account the mediating effects of building characteristics on the ingress of PM2.5 from outdoor sources and its impact on population exposure in the indoor domestic environment. This study describes how building simulation can be used to determine the indoor concentration of outdoor-sourced pollution for different housing typologies and how the results can be mapped using building stock models and Geographical Information Systems software to demonstrate the modifying effect of dwellings on occupant exposure to PM2.5 across London. Building archetypes broadly representative of those in the Greater London Authority were simulated for pollution infiltration using EnergyPlus. In addition, the influence of occupant behavior on indoor levels of PM2.5 from outdoor sources was examined using a temperature-dependent window-opening scenario. Results demonstrate a range of I/O ratios of PM2.5, with detached and semi-detached dwellings most vulnerable to high levels of infiltration. When the results are mapped, central London shows lower I/O ratios of PM2.5 compared with outer London, an apparent inversion of exposure most likely caused by the prevalence of flats rather than detached or semi-detached properties. PMID:24713025

  20. A green approach towards adoption of chemical reaction model on 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane decomposition by differential isoconversional kinetic analysis.

    PubMed

    Das, Mitali; Shu, Chi-Min

    2016-01-15

    This study investigated the thermal degradation products of 2,5-dimethyl-2,5-di-(tert-butylperoxy) hexane (DBPH), by TG/GC/MS to identify runaway reaction and thermal safety parameters. It also included the determination of time to maximum rate under adiabatic conditions (TMR(ad)) and self-accelerating decomposition temperature obtained through Advanced Kinetics and Technology Solutions. The apparent activation energy (Ea) was calculated from differential isoconversional kinetic analysis method using differential scanning calorimetry experiments. The Ea value obtained by Friedman analysis is in the range of 118.0-149.0 kJ mol(-1). The TMR(ad) was 24.0 h with an apparent onset temperature of 82.4°C. This study has also established an efficient benchmark for a thermal hazard assessment of DBPH that can be applied to assure safer storage conditions. PMID:26368796

  1. Ambiphilic boron in 1,4,2,5-diazadiborinine

    PubMed Central

    Wang, Baolin; Li, Yongxin; Ganguly, Rakesh; Hirao, Hajime; Kinjo, Rei

    2016-01-01

    Boranes have long been known as the archetypal Lewis acids owing to an empty p-orbital on the boron centre. Meanwhile, Lewis basic tricoordinate boranes have been developed in recent years. Here we report the synthesis of an annulated 1,4,2,5-diazadiborinine derivative featuring boron atoms that exhibit both Lewis acidic and basic properties. Experimental and computational studies confirmed that two boron atoms in this molecule are spectroscopically equivalent. Nevertheless, this molecule cleaves C–O, B–H, Si–H and P–H bonds heterolytically, and readily undergoes [4+2] cycloaddition reaction with non-activated unsaturated bonds such as C=O, C=C, C≡C and C≡N bonds. The result, thus, indicates that the indistinguishable boron atoms in 1,4,2,5-diazadiborinine act as both nucleophilic and electrophilic centres, demonstrating ambiphilic nature. PMID:27279265

  2. Ambiphilic boron in 1,4,2,5-diazadiborinine.

    PubMed

    Wang, Baolin; Li, Yongxin; Ganguly, Rakesh; Hirao, Hajime; Kinjo, Rei

    2016-01-01

    Boranes have long been known as the archetypal Lewis acids owing to an empty p-orbital on the boron centre. Meanwhile, Lewis basic tricoordinate boranes have been developed in recent years. Here we report the synthesis of an annulated 1,4,2,5-diazadiborinine derivative featuring boron atoms that exhibit both Lewis acidic and basic properties. Experimental and computational studies confirmed that two boron atoms in this molecule are spectroscopically equivalent. Nevertheless, this molecule cleaves C-O, B-H, Si-H and P-H bonds heterolytically, and readily undergoes [4+2] cycloaddition reaction with non-activated unsaturated bonds such as C=O, C=C, C≡C and C≡N bonds. The result, thus, indicates that the indistinguishable boron atoms in 1,4,2,5-diazadiborinine act as both nucleophilic and electrophilic centres, demonstrating ambiphilic nature. PMID:27279265

  3. PLSS 2.5 Fan Design and Development

    NASA Technical Reports Server (NTRS)

    Quinn, Gregory; Carra, Michael; Converse, David; Chullen, Cinda

    2015-01-01

    NASA is building a high fidelity prototype of an advanced portable life support system (PLSS) as part of the Advanced Exploration Systems Program. This new PLSS, designated as PLSS 2.5, will advance component technologies and systems knowledge in order to inform a future flight program. The oxygen ventilation loop of its predecessor, PLSS 2.0, is driven by a centrifugal fan developed using specifications from the Constellation Program. PLSS technology and system parameters have matured to the point where the existing fan will not perform adequately for the new prototype. In addition, areas of potential improvement have been identified with the existing fan that could be addressed in a new design. As a result, a new fan was designed and tested for the PLSS 2.5.

  4. Seasonal and diurnal variation of PM2.5 over eight major sites of southeast Texas

    NASA Astrophysics Data System (ADS)

    Narendra, Vijay

    PM2.5 is a section of the vast amount of particulates in the atmosphere. Some occur naturally, some are anthropogenic. A section of this work deals with the important sources of PM2.5 and its adverse effects on climate and human health. The concentration of PM2.5 in the atmosphere varies each day, depending on the season of the year, and it is different for different sites. This study mainly deals with the study of the concentration of PM2.5 over eight major sites in Southeast Texas from 2003 to 2007 -- Beaumont, Orange, Port Arthur, Hamshire, Deer Park, Channelview, Aldine, and Houston East. Additionally, four more sites, two at the northern part of Texas -- Amarillo and Lubbock, and two at the Rio Grande region -- Brownsville and Mission, were also compared with the eight sites. The diurnal variation of the PM2.5 concentration produces two peaks, one in the morning and one during the evening. The average morning peak time shifts by two GMT hours between winter (November - March) and summer (May - September). On examining the various parameters involved with the formation of morning and evening peaks, it was found that the major influence on the peaks is the photochemical activity and other inconsequential factors like traffic and other forms of air pollution.

  5. Trifluoroacetic Acid Level in the Atmosphere of Beijing and Its Relationship with PM2.5

    NASA Astrophysics Data System (ADS)

    Guo, Junyu; Zhang, Jianbo

    2016-04-01

    Atmospheric concentrations of Trifluoroacetic Acid (TFA), one of the main degradation products of HCFC-123, HCFC-124 and HFC-134a, were detected in Beijing, China between 2013 and 2014. By analyzing the 137 atmospheric samples, the results showed that the annual mean atmospheric concentration of TFA was 1459±223 pg•m-3. TFA was mainly distributed in gaseous phase, for the concentration was 1396±225 pg•m-3, while that in particle phase was 62±8 pg•m-3. Considering the frequent occurrence of hazy weather in Beijing, the relationship between TFA and PM2.5 in atmosphere was analyzed. The correlation analysis shows that the proportion of particle phase in atmosphere concentration of TFA and mass concentration of PM2.5 are positively correlated with each other (P<0.001), indicating the particles have an absorption effect on TFA. At the same time, when mass concentration of PM2.5 in atmosphere is high, atmospheric concentration of TFA is relatively low. According to the correlation analysis, mass concentration of PM2.5 and atmospheric concentration of TFA are negatively correlated with each other (P=0.005). The main reason is very likely that particle's extinction for light can be enhanced as particle level rises, which causes TFA precursors photolysis to weaken. The results indicate that PM2.5 has a significant impact on TFA.

  6. Emissions inventory of PM2.5 trace elements across the United States

    SciTech Connect

    Adam Reff; Prakash V. Bhave; Heather Simon; Thompson G. Pace; George A. Pouliot; J. David Mobley; Marc Houyoux

    2009-08-15

    This paper presents the first National Emissions Inventory (NEI) of fine particulate matter (PM2.5) that includes the full suite of PM2.5 trace elements (atomic number >10) measured at ambient monitoring sites across the U.S. PM2.5 emissions in the NEI were organized and aggregated into a set of 84 source categories for which chemical speciation profiles are available (e.g., Unpaved Road Dust, Agricultural Soil, Wildfires). Emission estimates for ten metals classified as Hazardous Air Pollutants (HAP) were refined using data from a recent HAP NEI. All emissions were spatially gridded, and U.S. emissions maps for dozens of trace elements (e.g., Fe, Ti) are presented for the first time. Nationally, the trace elements emitted in the highest quantities are silicon (3.8 x 10{sup 5} ton/yr), aluminium (1.4 x 10{sup 5} ton/yr), and calcium (1.3 x 10{sup 5} ton/yr). Our chemical characterization of the PM2.5 inventory shows that most of the previously unspeciated emissions are comprised of crustal elements, potassium, sodium, chlorine, and metal-bound oxygen. Coal combustion is the largest source of S, Se, Sr, Hg and primary sulfates. This work also reveals that the largest PM2.5 sources lacking specific speciation data are off-road diesel-powered mobile equipment, road construction dust, marine vessels, gasoline-powered boats, and railroad locomotives. 28 refs., 4 figs.

  7. Estimating Error in Using Residential Outdoor PM2.5 Concentrations as Proxies for Personal Exposures: A Meta-analysis

    PubMed Central

    Avery, Christy L.; Mills, Katherine T.; Williams, Ronald; McGraw, Kathleen A.; Poole, Charles; Smith, Richard L.; Whitsel, Eric A.

    2010-01-01

    Background Studies examining the health effects of particulate matter ≤ 2.5 μm in aerodynamic diameter (PM2.5) commonly use ambient PM2.5 concentrations measured at distal monitoring sites as proxies for personal exposure and assume spatial homogeneity of ambient PM2.5. An alternative proxy—the residential outdoor PM2.5 concentration measured adjacent to participant homes—has few advantages under this assumption. Objectives We systematically reviewed the correlation between residential outdoor PM2.5 and personal PM2.5 (r̄j) as a means of comparing the magnitude and sources of measurement error associated with their use as exposure surrogates. Methods We searched seven electronic reference databases for studies of the within-participant residential outdoor-personal PM2.5 correlation. Results The search identified 567 candidate studies, nine of which were abstracted in duplicate, that were published between 1996 and 2008. They represented 329 nonsmoking participants 6–93 years of age in eight U.S. cities, among whom r̄j was estimated (median, 0.53; range, 0.25–0.79) based on a median of seven residential outdoor-personal PM2.5 pairs per participant. We found modest evidence of publication bias (symmetric funnel plot; pBegg = 0.4; pEgger = 0.2); however, we identified evidence of heterogeneity (Cochran’s Q-test p = 0.05). Of the 20 characteristics examined, earlier study midpoints, eastern longitudes, older mean age, higher outdoor temperatures, and lower personal-residential outdoor PM2.5 differences were associated with increased within-participant residential outdoor-personal PM2.5 correlations. Conclusions These findings were similar to those from a contemporaneous meta-analysis that examined ambient-personal PM2.5 correlations (r̄j = median, 0.54; range, 0.09–0.83). Collectively, the meta-analyses suggest that residential outdoor-personal and ambient-personal PM2.5 correlations merit greater consideration when evaluating the potential for bias

  8. 2.5D Cartoon Hair Modeling and Manipulation.

    PubMed

    Yeh, Chih-Kuo; Jayaraman, Pradeep Kumar; Liu, Xiaopei; Fu, Chi-Wing; Lee, Tong-Yee

    2015-03-01

    This paper addresses a challenging single-view modeling and animation problem with cartoon images. Our goal is to model the hairs in a given cartoon image with consistent layering and occlusion, so that we can produce various visual effects from just a single image. We propose a novel 2.5D modeling approach to deal with this problem. Given an input image, we first segment the hairs of the cartoon character into regions of hair strands. Then, we apply our novel layering metric, which is derived from the Gestalt psychology, to automatically optimize the depth ordering among the hair strands. After that, we employ our hair completion method to fill the occluded part of each hair strand, and create a 2.5D model of the cartoon hair. By using this model, we can produce various visual effects, e.g., we develop a simplified fluid simulation model to produce wind blowing animations with the 2.5D hairs. To further demonstrate the applicability and versatility of our method, we compare our results with real cartoon hair animations, and also apply our model to produce a wide variety of hair manipulation effects, including hair editing and hair braiding. PMID:26357063

  9. Spatiotemporal associations between GOES aerosol optical depth retrievals and ground-level PM2.5.

    PubMed

    Paciorek, Christopher J; Liu, Yang; Moreno-Macias, Hortensia; Kondragunta, Shobha

    2008-08-01

    We analyze the strength of association between aerosol optical depth (AOD) retrievals from the GOES aerosol/smoke product (GASP) and ground-level fine particulate matter (PM2.5) to assess AOD as a proxy for PM2.5 in the United States. GASP AOD is retrieved from a geostationary platform, giving half-hourly observations every day, in contrast to once per day snapshots from polar-orbiting satellites. However, GASP AOD is based on a less-sophisticated instrument and retrieval algorithm. We find that daily correlations between GASP AOD and PM2.5 over time at fixed locations are reasonably high, except in the winter and in the western U.S. Correlations over space at fixed times are lower. Simple averaging to the month and year actually reduces correlations over space, but statistical calibration allows averaging over time that produces moderately strong correlations. These results and the data density of GASP AOD highlight its potential to help improve exposure estimates for epidemiological analyses. On average 39% of days in a month have a GASP AOD retrieval compared to 11% for MODIS and 5% for MISR. Furthermore, GASP AOD has been retrieved since November 1994, providing a long-term record that predates the availability of most PM2.5 monitoring data and other satellite instruments. PMID:18754512

  10. Black carbon and particulate matter (PM2.5) concentrations in New York City's subway stations.

    PubMed

    Vilcassim, M J Ruzmyn; Thurston, George D; Peltier, Richard E; Gordon, Terry

    2014-12-16

    The New York City (NYC) subway is the main mode of transport for over 5 million passengers on an average weekday. Therefore, airborne pollutants in the subway stations could have a significant impact on commuters and subway workers. This study looked at black carbon (BC) and particulate matter (PM2.5) concentrations in selected subway stations in Manhattan. BC and PM2.5 levels were measured in real time using a Micro-Aethalometer and a PDR-1500 DataRAM, respectively. Simultaneous samples were also collected on quartz filters for organic and elemental carbon (OC/EC) analysis and on Teflon filters for gravimetric and trace element analysis. In the underground subway stations, mean real time BC concentrations ranged from 5 to 23 μg/m(3), with 1 min average peaks >100 μg/m(3), while real time PM2.5 levels ranged from 35 to 200 μg/m(3). Mean EC levels ranged from 9 to 12.5 μg/m(3). At street level on the same days, the mean BC and PM2.5 concentrations were below 3 and 10 μg/m(3), respectively. This study shows that both BC soot and PM levels in NYC's subways are considerably higher than ambient urban street levels and that further monitoring and investigation of BC and PM subway exposures are warranted. PMID:25409007

  11. Autoregressive spatially varying coefficients model for predicting daily PM2.5 using VIIRS satellite AOT

    NASA Astrophysics Data System (ADS)

    Schliep, E. M.; Gelfand, A. E.; Holland, D. M.

    2015-12-01

    There is considerable demand for accurate air quality information in human health analyses. The sparsity of ground monitoring stations across the United States motivates the need for advanced statistical models to predict air quality metrics, such as PM2.5, at unobserved sites. Remote sensing technologies have the potential to expand our knowledge of PM2.5 spatial patterns beyond what we can predict from current PM2.5 monitoring networks. Data from satellites have an additional advantage in not requiring extensive emission inventories necessary for most atmospheric models that have been used in earlier data fusion models for air pollution. Statistical models combining monitoring station data with satellite-obtained aerosol optical thickness (AOT), also referred to as aerosol optical depth (AOD), have been proposed in the literature with varying levels of success in predicting PM2.5. The benefit of using AOT is that satellites provide complete gridded spatial coverage. However, the challenges involved with using it in fusion models are (1) the correlation between the two data sources varies both in time and in space, (2) the data sources are temporally and spatially misaligned, and (3) there is extensive missingness in the monitoring data and also in the satellite data due to cloud cover. We propose a hierarchical autoregressive spatially varying coefficients model to jointly model the two data sources, which addresses the foregoing challenges. Additionally, we offer formal model comparison for competing models in terms of model fit and out of sample prediction of PM2.5. The models are applied to daily observations of PM2.5 and AOT in the summer months of 2013 across the conterminous United States. Most notably, during this time period, we find small in-sample improvement incorporating AOT into our autoregressive model but little out-of-sample predictive improvement.

  12. Heterogeneous 2.5D integration on through silicon interposer

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaowu; Lin, Jong Kai; Wickramanayaka, Sunil; Zhang, Songbai; Weerasekera, Roshan; Dutta, Rahul; Chang, Ka Fai; Chui, King-Jien; Li, Hong Yu; Wee Ho, David Soon; Ding, Liang; Katti, Guruprasad; Bhattacharya, Suryanarayana; Kwong, Dim-Lee

    2015-06-01

    Driven by the need to reduce the power consumption of mobile devices, and servers/data centers, and yet continue to deliver improved performance and experience by the end consumer of digital data, the semiconductor industry is looking for new technologies for manufacturing integrated circuits (ICs). In this quest, power consumed in transferring data over copper interconnects is a sizeable portion that needs to be addressed now and continuing over the next few decades. 2.5D Through-Si-Interposer (TSI) is a strong candidate to deliver improved performance while consuming lower power than in previous generations of servers/data centers and mobile devices. These low-power/high-performance advantages are realized through achievement of high interconnect densities on the TSI (higher than ever seen on Printed Circuit Boards (PCBs) or organic substrates), and enabling heterogeneous integration on the TSI platform where individual ICs are assembled at close proximity (<1 mm separation) compared with several centimeters on a typical PCB. In this paper, we have outlined the benefits of adopting 2.5D TSI technology and also highlighted the current day approaches to implement this technology in Si fabrication facilities, and in assembly/packaging factories. While the systems and devices that power the mobile society benefit from exploiting advantages of 2.5D integration on TSI, there do exist surmountable challenges that need to be addressed for this relatively new technology to be used in high volume production of next generation semiconductor devices. The key areas of focus and challenges include: Technology planning and design-execution that are necessary for harnessing 2.5D TSI for building systems, processing flow for the fabrication of 100 μm thick TSI at acceptable costs, manufacturing flow for assembling multiple ICs on a 100 μm thick TSI in a repeatable, and reliable manner, thermo-mechanical analysis and optimization for addressing warpage issues, and thermal

  13. Orbital-optimized MP2.5 and its analytic gradients: Approaching CCSD(T) quality for noncovalent interactions

    SciTech Connect

    Bozkaya, Uğur; Sherrill, C. David

    2014-11-28

    Orbital-optimized MP2.5 [or simply “optimized MP2.5,” OMP2.5, for short] and its analytic energy gradients are presented. The cost of the presented method is as much as that of coupled-cluster singles and doubles (CCSD) [O(N{sup 6}) scaling] for energy computations. However, for analytic gradient computations the OMP2.5 method is only half as expensive as CCSD because there is no need to solve λ{sub 2}-amplitude equations for OMP2.5. The performance of the OMP2.5 method is compared with that of the standard second-order Møller–Plesset perturbation theory (MP2), MP2.5, CCSD, and coupled-cluster singles and doubles with perturbative triples (CCSD(T)) methods for equilibrium geometries, hydrogen transfer reactions between radicals, and noncovalent interactions. For bond lengths of both closed and open-shell molecules, the OMP2.5 method improves upon MP2.5 and CCSD by 38%–43% and 31%–28%, respectively, with Dunning's cc-pCVQZ basis set. For complete basis set (CBS) predictions of hydrogen transfer reaction energies, the OMP2.5 method exhibits a substantially better performance than MP2.5, providing a mean absolute error of 1.1 kcal mol{sup −1}, which is more than 10 times lower than that of MP2.5 (11.8 kcal mol{sup −1}), and comparing to MP2 (14.6 kcal mol{sup −1}) there is a more than 12-fold reduction in errors. For noncovalent interaction energies (at CBS limits), the OMP2.5 method maintains the very good performance of MP2.5 for closed-shell systems, and for open-shell systems it significantly outperforms MP2.5 and CCSD, and approaches CCSD(T) quality. The MP2.5 errors decrease by a factor of 5 when the optimized orbitals are used for open-shell noncovalent interactions, and comparing to CCSD there is a more than 3-fold reduction in errors. Overall, the present application results indicate that the OMP2.5 method is very promising for open-shell noncovalent interactions and other chemical systems with difficult electronic structures.

  14. PM2.5 Spatiotemporal Variations and the Relationship with Meteorological Factors during 2013-2014 in Beijing, China

    PubMed Central

    Wang, Chao; Xu, Qin; Wang, Wei; Luo, Yanxia; Tao, Lixin; Gao, Qi; Guo, Jin; Chen, Sipeng; Cao, Kai; Liu, Long; Gao, Ni; Liu, Xiangtong; Yang, Kun; Yan, Aoshuang; Guo, Xiuhua

    2015-01-01

    Objective Limited information is available regarding spatiotemporal variations of particles with median aerodynamic diameter < 2.5 μm (PM2.5) at high resolutions, and their relationships with meteorological factors in Beijing, China. This study aimed to detect spatiotemporal change patterns of PM2.5 from August 2013 to July 2014 in Beijing, and to assess the relationship between PM2.5 and meteorological factors. Methods Daily and hourly PM2.5 data from the Beijing Environmental Protection Bureau (BJEPB) were analyzed separately. Ordinary kriging (OK) interpolation, time-series graphs, Spearman correlation coefficient and coefficient of divergence (COD) were used to describe the spatiotemporal variations of PM2.5. The Kruskal-Wallis H test, Bonferroni correction, and Mann-Whitney U test were used to assess differences in PM2.5 levels associated with spatial and temporal factors including season, region, daytime and day of week. Relationships between daily PM2.5 and meteorological variables were analyzed using the generalized additive mixed model (GAMM). Results Annual mean and median of PM2.5 concentrations were 88.07 μg/m3 and 71.00 μg/m3, respectively, from August 2013 to July 2014. PM2.5 concentration was significantly higher in winter (P < 0.0083) and in the southern part of the city (P < 0.0167). Day to day variation of PM2.5 showed a long-term trend of fluctuations, with 2–6 peaks each month. PM2.5 concentration was significantly higher in the night than day (P < 0.0167). Meteorological factors were associated with daily PM2.5 concentration using the GAMM model (R2 = 0.59, AIC = 7373.84). Conclusion PM2.5 pollution in Beijing shows strong spatiotemporal variations. Meteorological factors influence the PM2.5 concentration with certain patterns. Generally, prior day wind speed, sunlight hours and precipitation are negatively correlated with PM2.5, whereas relative humidity and air pressure three days earlier are positively correlated with PM2.5. PMID

  15. Estimation of anthropogenic PM2.5 emissions over Asian mega cities by integrating remote sensing and modeling

    NASA Astrophysics Data System (ADS)

    Kishi, H.; Takeuchi, W.; Sawada, H.

    2011-12-01

    Particulate matter whose aerodynamic diameter is less than 2.5 um (PM2.5) is one of the major pollutants that affect human health with causing asthma and even cancer. Emission standards for PM2.5 are establishing only in some countries and regions mainly because it is difficult to understand the atmospheric behaviors of PM2.5 spatially and temporally. This study aims to estimate atmospheric conditions focusing on PM2.5 with integrating remote sensing measurement and model estimation with bottom-up approach over global mega cities. Firstly, emitted PM2.5 is estimated by bottom-up approach modeling according to emissions sources such as exhaust emissions and biomass burning from 2000 to 2010 over global scale. They are estimated by developed model with paper review and land cover properties obtained by satellite measurements. Exhaust emission PM2.5 is estimated by total numbers of diesel vehicles in use, the number of population and emission standards regulated by governmental raw. Biomass burning PM2.5 is estimated by the number of hot spots detected by Moderate resolution imaging spectroradiometer (MODIS), fuel loading equivalent to the amount of field biomass, combustion factors estimated by vegetation moisture conditions and PM2.5 emission factors. Secondly, estimation errors of estimated PM2.5 emissions are evaluated by comparing reported PM2.5 emission inventories spatially and temporally. Black carbon and Organic carbon emissions estimated by Streets and REAS emission inventory are employed to compare model estimated PM2.5. Thirdly, integrated exhaust emissions and biomass burning PM2.5 is compared with MODIS Aerosol Optical Depth (AOD) measurement which is equivalent to total amount of PM2.5. Spatio-temporal patterns are analyzed between model estimated and satellite measured PM2.5. In case of Asian regions Easter than India, it is found that the highest PM2.5 concentration is observed in Hanoi 3.2 times higher than that in Tokyo over Asian mega cities

  16. Greater Capital Region Career Pathways Initiative

    ERIC Educational Resources Information Center

    Workforce Strategy Center, 2005

    2005-01-01

    This case study documents the activities of the Greater Capital Region Career Pathways Initiative (CPI), a partnership to develop regional, demand driven career pathways for the biotechnology sector in and around Albany, NY. This document is written for three primary audiences. First, it provides a report to the New York State Department of Labor…

  17. Spread of English across Greater China

    ERIC Educational Resources Information Center

    Feng, Anwei

    2012-01-01

    Greater China is used in this article to refer to mainland China, Hong Kong, Singapore, Taiwan and Macao. While a holistic approach is adopted to present and compare the rapid spread of English and development in English language education in these geographically close, and sociopolitically, culturally and economically interrelated but hugely…

  18. Waste Management in Greater Dhaka City.

    ERIC Educational Resources Information Center

    Rahman, M. H.

    1993-01-01

    This study focuses on the environmental degradation of Greater Dhaka City (GDC) resulting from pollution created by the indiscriminate disposal of industrial wastes, open dumping of solid wastes, inadequate treatment and disposal of domestic sewage, and unplanned disposal of leachate from agricultural land. Measures to protect the GDC environment…

  19. Signal phase switches offer greater dynamic range

    NASA Technical Reports Server (NTRS)

    Crow, R. B.

    1970-01-01

    Circuit, placed in the signal path of a closed-loop receiver to modulate telemetered data in the 10-MHz spectrum, improves signal-to-noise ratio by 3 db in a communication receiver. The switch enables bandwidth reduction which reduces noise overload on the following stages, giving the system greater dynamic range.

  20. Impact of urbanization level on urban air quality: a case of fine particles (PM(2.5)) in Chinese cities.

    PubMed

    Han, Lijian; Zhou, Weiqi; Li, Weifeng; Li, Li

    2014-11-01

    We examined and compared PM2.5 concentrations in urban and the surrounding regions, and further investigated the impact of urbanization on urban PM2.5 concentrations at the Chinese prefectures. Annual PM2.5 concentrations in most prefectures were greater than 10 μg/m(3), the air quality guideline of the World Health Organization. Those prefectures were mainly distributed along the east coast and southeast of Sichuan province; The urban PM2.5 concentrations ( [Formula: see text] ) in 85 cities were greater than (>10 μg/m(3)) those in the surrounding area. Those cities were mainly located in the Beijing-Sichuan and Shanghai-Guangxi belts. In addition, [Formula: see text] was less than (<0 μg/m(3)) that in surrounding areas in only 41 prefectures, which were located in western China or nearby mega cities; Significant positive correlations were found between [Formula: see text] and urban population (R(2) = 0.99, P < 0.05), and between [Formula: see text] and urban second industry fraction (R(2) = 0.71, P < 0.05), suggesting that urbanization had considerable impact on PM2.5 concentrations. PMID:25113968

  1. Ambient Fine Particulate (PM2.5) Air Pollution Attributable to Household Cooking Fuel in Asia

    NASA Astrophysics Data System (ADS)

    Chafe, Z.; Mehta, S.; Smith, K. R.

    2011-12-01

    Using the Greenhouse Gas and Air Pollution Interactions and Synergies (GAINS) model, hosted by the International Institute for Applied Systems Analysis (IIASA), we estimate the proportion of fine particulate ambient air pollution (PM2.5) attributable to household fuel use for cooking in Asia. This analysis considers primary anthropogenic PM2.5 emissions in two years: 1990 and 2005. Only emissions from household cooking fuels-not heating or lighting-are considered. Due to data availability, this analysis focuses solely on Asian countries, notably India and China which are home to about half of the households using solid fuel use worldwide. Forest and grassland fires, dust, and other "natural" particle sources were omitted from this analysis. The impact of emission sources on secondary particles from aerosol precursors was not determined. In China, the proportion of total primary anthropogenic PM2.5 attributable to household cooking decreased from 44% to 31% between 1990 and 2005. In India, the percent of primary anthropogenic PM2.5 emissions attributable to household cooking decreased from 55% to 49% between 1990 and 2005. Total mass change in primary anthropogenic PM2.5 emissions was much more variable by state in India, between 1990 and 2005, than by province in China (where there was a general downward trend in the total mass emitted). Similarly, growth in industrial emissions was much more variable at the sub-national level, between 1990 and 2005, in India than in China. Energy production played a more prominent role in the growth of primary anthropogenic PM2.5 emissions in India than it did in China. Forward-looking GAINS scenarios show that the contribution of household cooking to total primary anthropogenic PM2.5 emissions is much greater than that from on-road transport in India and China between 1990 and 2030. On-road cars, trucks, and other transport vehicles are, however, the cause of important pollutants other than PM2.5 (as are as cooking stoves that do

  2. Behavioral and environmental determinants of personal exposures to PM 2.5 in EXPOLIS - Helsinki, Finland

    NASA Astrophysics Data System (ADS)

    Koistinen, Kimmo J.; Hänninen, Otto; Rotko, Tuulia; Edwards, Rufus D.; Moschandreas, Demetrios; Jantunen, Matti J.

    Behavioral and environmental determinants of PM 2.5 personal exposures were analyzed for 201 randomly selected adult participants (25-55 years old) of the EXPOLIS study in Helsinki, Finland. Personal exposure concentrations were higher than respective residential outdoor, residential indoor and workplace indoor concentrations for both smokers and non-smokers. Mean personal exposure concentrations of active smokers (31.0±31.4 μg m -3) were almost double those of participants exposed to environmental tobacco smoke (ETS) (16.6±11.8 μg m -3) and three times those of participants not exposed to tobacco smoke (9.9±6.2 μg m -3). Mean indoor concentrations of PM 2.5 when a member of the household smoked indoors (20.8±23.9 μg m -3) were approximately 2.5 times the concentrations of PM 2.5 when no smoking was reported (8.2±5.2 μg m -3). Interestingly, however, both mean (8.2 μg m -3) and median (6.9 μg m -3) residential indoor concentrations for non-ETS exposed participants were lower than residential outdoor concentrations (9.5 and 7.3 μg m -3, respectively). In simple linear regression models residential indoor concentrations were the best predictors of personal exposure concentrations. Correlations ( r2) between PM 2.5 personal exposure concentrations of all participants, both smoking and non-smoking, and residential indoor, workplace indoor, residential outdoor and ambient fixed site concentrations were 0.53, 0.38, 0.17 and 0.16, respectively. Predictors for personal exposure concentrations of non-ETS exposed participants identified in multiple regression were residential indoor concentrations, workplace concentrations and traffic density in the nearest street from home, which accounted for 77% of the variance. Subsequently, step-wise regression not including residential and workplace indoor concentrations as input (as these are frequently not available), identified ambient PM 2.5 concentration and home location, as predictors of personal exposure

  3. PM2.5 and survival among older adults: Effect modification by particulate composition

    PubMed Central

    Kioumourtzoglou, Marianthi-Anna; Austin, Elena; Koutrakis, Petros; Dominici, Francesca; Schwartz, Joel; Zanobetti, Antonella

    2015-01-01

    Background Fine particulate (PM2.5) air pollution has been consistently linked to survival, but reported effect estimates are geographically heterogeneous. Exposure to different types of particle mixtures may explain some of this variation. Methods We used k-means cluster analyses to identify cities with similar pollution profiles, (i.e. PM2.5 composition) across the US. We examined the impact of PM2.5 on survival, and its variation across clusters of cities with similar PM2.5 composition, among Medicare enrollees in 81 US cities (2000–2010). We used time-varying annual PM2.5 averages, measured at ambient central monitoring sites, as the exposure of interest. We ran by-city Cox models, adjusting for individual data on previous cardiopulmonary-related hospitalizations and stratifying by follow-up time, age, gender and race. This eliminates confounding by factors varying across cities and long-term trends, focusing on year-to-year variations of air pollution around its city-specific mean and trend. We then pooled the city-specific effects using a random effects meta-regression. In this second stage, we also assessed effect modification by cluster membership and estimated cluster-specific PM2.5 effects. Results We followed more than 19 million subjects and observed more than 6 million deaths. We found a harmful impact of annual PM2.5 concentrations on survival (HR = 1.11 [95% confidence interval = 1.01–1.23] per 10 µg/m3). This effect was modified by particulate composition, with higher effects observed in clusters containing high concentrations of nickel, vanadium and sulfate. For instance, our highest effect estimate was observed in cities with harbors in the Northwest, characterized by high nickel, vanadium and elemental carbon concentrations (1.9 [1.1–3.3]). We observed null or negative associations in clusters with high oceanic and crustal particles. Conclusions To our knowledge, this is the first study to examine the association between PM2.5 composition

  4. Assessment of Population and Microenvironmental Exposure to Fine Particulate Matter (PM2.5)

    NASA Astrophysics Data System (ADS)

    Jiao, Wan

    A positive relationship exists between fine particulate matter (PM 2.5) exposure and adverse health effects. PM2.5 concentration-response functions used in the quantitative risk assessment were based on findings from human epidemiological studies that relied on areawide ambient concentrations as surrogate for actual ambient exposure, which cannot capture the spatial and temporal variability in human exposures. The goal of the study is to assess inter-individual, geographic and seasonal variability in population exposures to inform the interpretation of available epidemiological studies, and to improve the understanding of how exposure-related factors in important exposure microenvironments contribute to the variability in individual PM2.5 exposure. Typically, the largest percentage of time in which an individual is exposed to PM2.5 of ambient origin occurs in indoor residence, and the highest ambient PM2.5 concentrations occur in transportation microenvironments because of the proximity to on-road traffic emissions. Therefore, indoor residence and traffic-related transportation microenvironments were selected for further assessment in the study. Population distributions of individual daily PM2.5 exposures were estimated for the selected regions and seasons using the Stochastic Human Exposure and Dose Simulation Model for Particulate Matter (SHEDS-PM). For the indoor residence, the current practice by assuming the entire residence to be one large single zone for calculating the indoor residential PM 2.5 concentration was evaluated by applying an indoor air quality model, RISK, to compare indoor PM2.5 concentrations between single-zone and multi-zone scenarios. For the transportation microenvironments, one field data collection focused on in-vehicle microenvironment and was conducted to quantify the variability in the in-vehicle PM2.5 concentration with respect to the outside vehicle concentration for a wide range of conditions that affect intra-vehicle variability

  5. THE RELATIONSHIP BETWEEN REAL-TIME AND TIME-INTEGRATED COARSE (2.5-10MM), INTERMEDIATE (1-2.5MM), AND FINE (<2.5MM) PARTICULATE MATTER IN THE LOS ANGELES BASIN

    EPA Science Inventory

    Population exposure to ambient particulate matter (PM) has received considerable attention due to the association between ambient particulate concentrations and mortality. Current toxicological and epidemiological studies and controlled human and animal exposures suggest that a...

  6. Comparative evaluation of the impact of WRF/NMM and WRF/ARW meteorology on CMAQ simulations for PM2.5 and its related precursors during the 2006 TexAQS/GoMACCS study

    NASA Astrophysics Data System (ADS)

    Yu, S.; Mathur, R.; Pleim, J.; Pouliot, G.; Wong, D.; Eder, B.; Schere, K.; Gilliam, R.; Rao, S. T.

    2012-05-01

    This study presents a comparative evaluation of the impact of WRF-NMM and WRF-ARW meteorology on CMAQ simulations of PM2.5, its composition and related precursors over the eastern United States with the intensive observations obtained by aircraft (NOAA WP-3), ship and surface monitoring networks (AIRNow, IMPROVE, CASTNet and STN) during the 2006 TexAQS/GoMACCS study. The results at the AIRNow surface sites show that both ARW-CMAQ and NMM-CMAQ reproduced day-to-day variations of observed PM2.5 and captured the majority of observed PM2.5 within a factor of 2 with a NMB value of -0.4% for ARW-CMAQ and -18% for NMM-CMAQ. Both models performed much better at the urban sites than at the rural sites, with greater underpredictions at the rural sites. Both models consistently underestimated the observed PM2.5 at the rural IMPROVE sites by -1% for the ARW-CMAQ and -19% for the NMM-CMAQ. The greater underestimations of SO42-, OC and EC by the NMM-CMAQ contributed to increased underestimation of PM2.5 at the IMPROVE sites. The NMB values for PM2.5 at the STN urban sites are 15% and -16% for the ARW-CMAQ and NMM-CMAQ, respectively. The underestimation of PM2.5 at the STN sites by the NMM-CMAQ mainly results from the underestimations of the SO42-, NH4+ and TCM components, whereas the overestimation of PM2.5 at the STN sites by the ARW-CMAQ results from the overestimations of SO42-, NO3-, and NH4+. The Comparison with WP-3 aircraft measurements reveals that both ARW-CMAQ and NMM-CMAQ have very similar model performance for vertical profiles for PM2.5 chemical components (SO42-, NH4+) and related gaseous species (HNO3, SO2, NH3, isoprene, toluene, terpenes) as both models used the same chemical mechanisms and emissions. The results of ship along the coast of southeastern Texas over the Gulf of Mexico show that both models captured the temporal variations and broad synoptic change seen in the observed HCHO and acetaldehyde with the means NMB <30% most of the time but they

  7. On relationship between aerosols and PM2.5

    NASA Astrophysics Data System (ADS)

    Sano, Itaru; Mukai, Sonoyo; Nakata, Makiko

    2015-04-01

    Since aerosol optical thickness (AOT) is a key parameter of aerosols and description of the Earth's radiation budget, it is widely measured from ground sun photometer network NASA/AERONET [Holben et al., 1998] and from satellite. Fine and surface level aerosol particle called PM2.5, whose diameter is 2.5 μ m or less, is a well-known parameter for understanding polluted level of air. Smirnov et al. reported a good agreement between ground based AERONET AOT (870 nm) and dust concentrations at Barbados [Smirnov et al., 2000]. Wang and Christopher founded a good correlation between satellite based MODIS AOT product and PM2.5 in Alabama area [Wang and 2003]. Long range transported dusts, particularly Asian dust events, are easy to change the vertical profile of aerosol extinction. The vertical profile is important to estimate PM information because both AOT information measured from ground or satellite are integrated value of aerosol extinction from ground to space, i.e. columnar AOT. Thus, we have also proposed correlations between ground level PM2.5 and AERONET AOT (670 nm) in two cases of ordinary air condition and dusty days [Sano et al., 2010]. In this work, we investigate the relationship between PM2.5 and AERONET AOT considering LIDAR measurements. Note that all of instruments are set up at the roof of the University building (50 m) and collocated in 10 m area. Surface-level AOT is derived from AERONET AOT multiplied by an averaged vertical aerosol extinction given by LIDAR. Note that the definition of surface-level AOT in this work is assumed as AOT up to 500 m height. Introduction of surface-level AOT enables to avoid the contamination of dusty aerosol signal existing at high altitude from columnar AOT. The cloud aerosol imager (CAI) on GOSAT satellite has four observing wavelengths, 380, 670, 870 nm, and 1.6 μ m. In this work three channels are selected to estimate aerosol information. Look-up table (LUT) method is applied to estimate the optical properties

  8. Vibrational spectrum and internal rotation in 2,5-dimethylpyrazine

    NASA Astrophysics Data System (ADS)

    Arenas, J. F.; López-Navarrete, J. T.; Marcos, J. I.; Otero, J. C.

    1987-11-01

    The infrared and Raman spectra of 2,5-dimethylpyrazine have been recorded and assigned on the basis of a C2h molecular geometry previously determined by MINDO/3. The potential energy function corresponding to the internal rotation of both methyl groups has been used to solve the Schrödinger equation, and to obtain the energy levels of that motion on the basis of a molecular symmetry G36. The rotation of each substituent is found to be almost independent of the other.

  9. AMBIENT PM2.5 SAMPLING AND ANALYSIS

    SciTech Connect

    Unknown

    2000-10-01

    This report summarizes observations and tentative conclusions drawn from evaluations of the data captured to date from the operation of the ambient PM{sub 2.5} speciation sites in a geographical area encompassing southeastern Ohio, western Pennsylvania, and northwestern West Virginia. The overall goal of this program, called the Upper Ohio River Valley Project (UORVP), is to better understand the relationship between coal-based power system emissions and ambient air quality in the upper Ohio River Valley region through the collection of chemically resolved or speciated data.

  10. Determination and source identification of priority polycyclic aromatic hydrocarbons in PM2.5 in Taiyuan, China

    NASA Astrophysics Data System (ADS)

    Zhang, Meng; Xie, Jingfang; Wang, Zhentao; Zhao, Lijuan; Zhang, Hong; Li, Meng

    2016-09-01

    Sixteen polycyclic aromatic hydrocarbons (PAHs) present in PM2. 5 were analyzed in 2012 in Taiyuan (China) using high performance liquid chromatography (HPLC) with fluorescence and ultraviolet detectors. The average daily mass concentrations of ΣPAHs in different seasons ranged from 10.36 ng/m3 to 215.93 ng/m3 and had strong seasonal variation, with highest values in winter and lowest in summer. Over the whole year, PAHs appeared in the following order of frequency: 4-ring > 6-ring > 5-ring > 3-ring; in winter, the percentage of 4-ring PAHs was the highest (62.68%), while in summer, the percentages of 5-ring and 6-ring PAHs (cumulative total of 50.57%) were higher. The ratio method was employed to investigate potential source categories of PAHs in PM2.5 in Taiyuan, with data suggesting that the main PAH sources are coal and wood combustion and vehicle emissions. Finally, a risk assessment of PAHs was performed based on benzo(a)pyrene equivalent (BaPeq) values and individual cancer risk ratios, with results suggesting that the toxicity of PAHs was high during winter and spring time in Taiyuan. The values of incremental lifetime cancer risk (ILCR) induced by whole year inhalation exposure(Ri) for all age groups were larger than 10- 6 in spring and winter, while Ri values for male and female adults in summer and autumn were also larger than 10- 6, indicating high potential carcinogenic risk. During the same season, the ILCR of adults was greater than that of other age groups and that of females was a little higher than of males. With respect to the season, the ranking of ILCR in decreasing order was as follows: winter, spring, autumn, and summer.

  11. Measuring in-cabin school bus tailpipe and crankcase PM2.5: a new dual tracer method.

    PubMed

    Ireson, Robert G; Ondov, John M; Zielinska, Barbara; Weaver, Christopher S; Easter, Michael D; Lawson, Douglas R; Hesterberg, Thomas W; Davey, Mark E; Liu, L-J Sally

    2011-05-01

    Exposures of occupants in school buses to on-road vehicle emissions, including emissions from the bus itself, can be substantially greater than those in outdoor settings. A dual tracer method was developed and applied to two school buses in Seattle in 2005 to quantify in-cabin fine particulate matter (PM2.5) concentrations attributable to the buses' diesel engine tailpipe (DPMtp) and crankcase vent (PMck) emissions. The new method avoids the problem of differentiating bus emissions from chemically identical emissions of other vehicles by using a fuel-based organometallic iridium tracer for engine exhaust and by adding deuterated hexatriacontane to engine oil. Source testing results showed consistent PM:tracer ratios for the primary tracer for each type of emissions. Comparisons of the PM:tracer ratios indicated that there was a small amount of unburned lubricating oil emitted from the tailpipe; however, virtually no diesel fuel combustion products were found in the crankcase emissions. For the limited testing conducted here, although PMck emission rates (averages of 0.028 and 0.099 g/km for the two buses) were lower than those from the tailpipe (0.18 and 0.14 g/km), in-cabin PMck concentrations averaging 6.8 microg/m3 were higher than DPMtp (0.91 microg/m3 average). In-cabin DPMtp and PMck concentrations were significantly higher with bus windows closed (1.4 and 12 microg/m3, respectively) as compared with open (0.44 and 1.3 microg/m3, respectively). For comparison, average closed- and open-window in-cabin total PM2.5 concentrations were 26 and 12 microg/m3, respectively. Despite the relatively short in-cabin sampling times, very high sensitivities were achieved, with detection limits of 0.002 microg/m3 for DPMtp and 0.05 microg/m3 for PMck. PMID:21608489

  12. Contributions of open crop straw burning emissions to PM2.5 concentrations in China

    NASA Astrophysics Data System (ADS)

    Zhang, Libo; Liu, Yongqiang; Hao, Lu

    2016-01-01

    PM2.5 inventories have been developed in major Chinese cities to quantify the contributions from various sources based on annual emissions. This approach, however, could substantially underestimate the contribution from open straw burning during the harvest or other active burning periods. This study examines this issue by estimating monthly and annual straw-burning PM2.5 emissions in China and comparing with them with the corresponding emissions from other anthropogenic sources. Annually burned straw PM2.5 emissions during 1997 ∼ 2013 for 31 China provinces were calculated based on crop and related burning information for 12 months based on satellite detection of agricultural burning. Annual emissions from other anthropogenic sources were collected from the literature and allocated to monthly values using air pollution index measurements. The results indicate that the annual PM2.5 emissions from open straw burning in China were 1.036 m tons. The monthly PM2.5 emission ratios of straw burning to other anthropogenic sources during June, the harvest period for many regions, were several times larger than the annual ratios at national, regional, and province levels, suggesting that, in contrast to annual emissions that were used in the PM2.5 inventories in Chinese cities to assess the contributions from other sources, monthly emissions should be used to assess the contributions from straw burning during the harvest or other active burning periods. The larger contributions from straw burning shown in this study also suggest that substantial reduction of open field straw burning would dramatically improve air quality in many Chinese regions during the harvest or other active burning periods.

  13. Air Pollution Exposure Model for Individuals (EMI) in Health Studies: Evaluation for Ambient PM2.5 in Central North Carolina

    EPA Science Inventory

    Air pollution health studies of fine particulate matter (diameter ≤2.5 μm, PM2.5) often use outdoor concentrations as exposure surrogates. Failure to account for variability of indoor infiltration of ambient PM2.5 and time indoors can induce exposure errors. We developed an...

  14. ADVANCES IN CONTROL OF PM2..5 AND PM2..5 PRECURSORS GENERATED BY THE COMBUSTION OF PULVERIZED COAL

    EPA Science Inventory

    Particulate matter smaller than 2.5 micrometers in aerodynamic diameter (PM2.5) is of concern due to adverse health effects associated with elevated ambient mass concentrations of PM2.5. PM2.5 from coal-fired utility boilers is composed of directly emitted (primary) particles and...

  15. Direct Exchange of Oxygen and Selenium Atoms in the 1,2,5-Oxadiazoles and 1,2,5-Selenadiazoles by Action of Sulfur Monochloride.

    PubMed

    Konstantinova, Lidia S; Knyazeva, Ekaterina A; Rakitin, Oleg A

    2015-01-01

    A short synthetic approach to fused 1,2,5-thiadiazoles from the corresponding 1,2,5-oxadiazoles and 1,2,5-selenadiazoles has been developed. Mono- and bis(1,2,5-thiadiazoles) were selectively obtained in high yields. The pathways for these novel reactions were discussed. PMID:26274942

  16. Greater sadness reactivity in late life

    PubMed Central

    Seider, Benjamin H.; Shiota, Michelle N.; Whalen, Patrick

    2011-01-01

    Although previous research suggests that overall emotional reactivity does not change with normal aging, it is possible that different emotions follow different developmental courses. We examined emotional reactivity to films selected to elicit sadness, disgust, and a neutral state in young, middle-aged and older adults (total N = 222). Physiology and expressive behavior were measured continuously and reports of subjective emotional experience were obtained following each film. Results indicated that older adults reported greater sadness in response to all films and greater physiological responses to the sadness film than did the younger age groups. There were no age differences found in self-reported disgust or in behavioral expressions of sadness or disgust in response to any film. The age differences that were found were maintained even after controlling for pre-film self-reported sadness and for personal experiences of loss. These findings support the notion that sadness reactivity is heightened with age. PMID:20650943

  17. Genomic landscape of the Greater Middle East.

    PubMed

    Özçelik, Tayfun; Onat, Onur Emre

    2016-08-30

    Study of the Greater Middle East (GME), home to approximately 10% of the world's population, has made invaluable contributions to the characterization of rare genetic disease, especially recessive conditions arising from the tradition of consanguinity and large families with multiple children. A new study now reports 1,111 unrelated exomes from the GME and provides a comprehensive view of genetic variation for enhanced discovery of disease-associated genes. PMID:27573686

  18. Measurements of PM2.5 in megacity

    NASA Astrophysics Data System (ADS)

    Nakata, M.; Sano, I.; Mukai, S.

    2013-10-01

    Air pollution in megacities has become a serious problem. Fine particles called PM2.5, with a diameter of 2.5 micrometres or less, are particularly problematic. Our observation site, located in eastern Osaka, is home to many smalland medium-scale manufacturing enterprises. A clear atmosphere is rare in this area, and the air is usually polluted with suspended particles emitted from diesel vehicles and industries. Furthermore, pollutants carried by winds from China add to the levels of pollution in the atmosphere. In this work, we investigate the size and composition of particulate matter with a scanning electron microscope (SEM) coupled with an energy-dispersive X-ray analyser (EDX). We use sampling data from an PM sampler mounted on the roof of a building at Kinki University at a height of about 50 m above sea level. It is evident that aerosol properties such as the amount, size, shape, and composition, change when anthropogenic or dust aerosol is transported. The level of sulphate and the percentage of fine particle increase in severe air pollution. In contrast, it is clear that silicon, which is possibly derived from soil particles, becomes dominant and that the number of large particles increase during the dust event.

  19. Myopes experience greater contrast adaptation during reading.

    PubMed

    McGonigle, Colm; van der Linde, Ian; Pardhan, Shahina; Engel, Stephen A; Mallen, Edward A H; Allen, Peter M

    2016-04-01

    In this study, we investigated whether reading influences contrast adaptation differently in young adult emmetropic and myopic participants at the spatial frequencies created by text rows and character strokes. Pre-adaptation contrast sensitivity was measured for test gratings with spatial frequencies of 1cdeg(-1) and 4cdeg(-1), presented horizontally and vertically. Participants then adapted to reading text corresponding to the horizontal "row frequency" of text (1cdeg(-1)), and vertical "stroke frequency" of the characters (4cdeg(-1)) for 180s. Following this, post-adaptation contrast sensitivity was measured. Twenty young adults (10 myopes, 10 emmetropes) optimally corrected for the viewing distance participated. There was a significant reduction in logCS post-text adaptation (relative to pre-adaptation logCS) at the row frequency (1cdeg(-1) horizontal) but not at the stroke frequency (4cdeg(-1) vertical). logCS changes due to adaptation at 1cdeg(-1) horizontal were significant in both emmetropes and myopes. Comparing the two refractive groups, myopic participants showed significantly greater adaptation compared to emmetropic participants. Reading text on a screen induces contrast adaptation in young adult observers. Myopic participants were found to exhibit greater contrast adaptation than emmetropes at the spatial frequency corresponding to the text row frequency. No contrast adaptation was observed at the text stroke frequency in either participant group. The greater contrast adaptation experienced by myopes after reading warrants further investigation to better understand the relationship between near work and myopia development. PMID:26804636

  20. Greater trochanter apophysitis in the adolescent athlete.

    PubMed

    Young, Simon W; Safran, Marc R

    2015-05-01

    Lower limb traction apophysitis is common in young athletes, occurring at sites such as the tibial tubercle (Osgood-Schlatter disease) and distal patella (Sinding-Larsen-Johansson disease). Around the hip, iliac apophysitis is well recognized, but no cases of greater trochanter apophysitis have previously been reported. We describe the case of a 15-year-old male basketball player with a 2-month history of the right hip pain and significant functional limitation. X-rays revealed widening of the greater trochanter apophysis with subchondral sclerosis, consistent with a diagnosis of traction apophysitis. The patient was treated with a period of relative rest and anti-inflammatory medication. He gradually returned to full athletic activity, including basketball, without recurrence of pain or limitation. We describe the first reported case of traction apophysitis of the greater trochanter. The unique muscular anatomy of this apophysis with balanced forces explains the rarity of this condition. If encountered, rest and activity modification is the recommended treatment. PMID:24942622

  1. Analysis of the relationship between PM2.5 and lung cancer based on protein-protein interactions.

    PubMed

    Shu, Yang; Zhu, Liucun; Yuan, Fei; Kong, Xiangyin; Huang, Tao; Cai, Yu-Dong

    2016-01-01

    Lung cancer, characterized by uncontrolled cell growth in tissues of the lung, is one of the leading causes of cancer mortality worldwide. Many etiologic factors for lung cancer tumorigenesis have been identified to date, such as smoking and exposure to radon, cooking fumes and asbestos. Atmospheric pollution has become increasingly heavy in China in recent years. Accordingly, greater numbers of people are paying attention to the air quality around them. PM2.5 (particulate matter with a diameter of 2.5 micrometers or less), which is one of the most important indicators for measuring air quality, can penetrate and be retained in lung tissue. It is believed that PM2.5 may represent a new type of etiological factor for lung cancer. This study constitutes the analysis of the association between PM2.5 and lung cancer. Genes related to small/nonsmall cell lung cancer were evaluated by assigning scores to measure the impact caused by PM2.5. Analyses of small/nonsmall cell lung cancer genes with high scores revealed that it is theoretically possible that PM2.5 is an etiologic factor for lung cancer. Our results provided new insights of the relationship between lung cancers and air pollution. PMID:26552437

  2. On-road PM2.5 pollution exposure in multiple transport microenvironments in Delhi

    NASA Astrophysics Data System (ADS)

    Goel, Rahul; Gani, Shahzad; Guttikunda, Sarath K.; Wilson, Daniel; Tiwari, Geetam

    2015-12-01

    PM2.5 pollution in Delhi averaged 150 μg/m3 from 2012 through 2014, which is 15 times higher than the World Health Organization's annual-average guideline. For this setting, we present on-road exposure of PM2.5 concentrations for 11 transport microenvironments along a fixed 8.3-km arterial route, during morning rush hour. The data collection was carried out using a portable TSI DustTrak DRX 8433 aerosol monitor, between January and May (2014). The monthly-average measured ambient concentrations varied from 130 μg/m3 to 250 μg/m3. The on-road PM2.5 concentrations exceeded the ambient measurements by an average of 40% for walking, 10% for cycle, 30% for motorised two wheeler (2W), 30% for open-windowed (OW) car, 30% for auto rickshaw, 20% for air-conditioned as well as for OW bus, 20% for bus stop, and 30% for underground metro station. On the other hand, concentrations were lower by 50% inside air-conditioned (AC) car and 20% inside the metro rail carriage. We find that the percent exceedance for open modes (cycle, auto rickshaw, 2W, OW car, and OW bus) reduces non-linearly with increasing ambient concentration. The reduction is steeper at concentrations lower than 150 μg/m3 than at higher concentrations. After accounting for air inhalation rate and speed of travel, PM2.5 mass uptake per kilometer during cycling is 9 times of AC car, the mode with the lowest exposure. At current level of concentrations, an hour of cycling in Delhi during morning rush-hour period results in PM2.5 dose which is 40% higher than an entire-day dose in cities like Tokyo, London, and New York, where ambient concentrations range from 10 to 20 μg/m3.

  3. On-road PM2.5 pollution exposure in multiple transport microenvironments in Delhi

    NASA Astrophysics Data System (ADS)

    Goel, Rahul; Gani, Shahzad; Guttikunda, Sarath K.; Wilson, Daniel; Tiwari, Geetam

    2015-12-01

    PM2.5 pollution in Delhi averaged 150 μg/m3 from 2012 through 2014, which is 15 times higher than the World Health Organization's annual-average guideline. For this setting, we present on-road exposure of PM2.5 concentrations for 11 transport microenvironments along a fixed 8.3-km arterial route, during morning rush hour. The data collection was carried out using a portable TSI DustTrak DRX 8433 aerosol monitor, between January and May (2014). The monthly-average measured ambient concentrations varied from 130 μg/m3 to 250 μg/m3. The on-road PM2.5 concentrations exceeded the ambient measurements by an average of 40% for walking, 10% for cycle, 30% for motorised two wheeler (2W), 30% for open-windowed (OW) car, 30% for auto rickshaw, 20% for air-conditioned as well as for OW bus, 20% for bus stop, and 30% for underground metro station. On the other hand, concentrations were lower by 50% inside air-conditioned (AC) car and 20% inside the metro rail carriage. We find that the percent exceedance for open modes (cycle, auto rickshaw, 2W, OW car, and OW bus) reduces non-linearly with increasing ambient concentration. The reduction is steeper at concentrations lower than 150 μg/m3 than at higher concentrations. After accounting for air inhalation rate and speed of travel, PM2.5 mass uptake per kilometer during cycling is 9 times of AC car, the mode with the lowest exposure. At current level of concentrations, an hour of cycling in Delhi during morning rush-hour period results in PM2.5 dose which is 40% higher than an entire-day dose in cities like Tokyo, London, and New York, where ambient concentrations range from 10 to 20 μg/m3.

  4. Analysis of airborne particulate matter (PM2.5) over Hong Kong using remote sensing and GIS.

    PubMed

    Shi, Wenzhong; Wong, Man Sing; Wang, Jingzhi; Zhao, Yuanling

    2012-01-01

    Airborne fine particulates (PM(2.5); particulate matter with diameter less than 2.5 μm) are receiving increasing attention for their potential toxicities and roles in visibility and health. In this study, we interpreted the behavior of PM(2.5) and its correlation with meteorological parameters in Hong Kong, during 2007-2008. Significant diurnal variations of PM(2.5) concentrations were observed and showed a distinctive bimodal pattern with two marked peaks during the morning and evening rush hour times, due to dense traffic. The study observed higher PM(2.5) concentrations in winter when the northerly and northeasterly winds bring pollutants from the Chinese mainland, whereas southerly monsoon winds from the sea bring fresh air to the city in summer. In addition, higher concentrations of PM(2.5) were observed in rush hours on weekdays compared to weekends, suggesting the influence of anthropogenic activities on fine particulate levels, e.g., traffic-related local PM(2.5) emissions. To understand the spatial pattern of PM(2.5) concentrations in the context of the built-up environment of Hong Kong, we utilized MODerate Resolution Imaging Spectroradiometer (MODIS) Aerosol Optical Thickness (AOT) 500 m data and visibility data to derive aerosol extinction profile, then converted to aerosol and PM(2.5) vertical profiles. A Geographic Information Systems (GIS) prototype was developed to integrate atmospheric PM(2.5) vertical profiles with 3D GIS data. An example of the query function in GIS prototype is given. The resulting 3D database of PM(2.5) concentrations provides crucial information to air quality regulators and decision makers to comply with air quality standards and in devising control strategies. PMID:22969323

  5. Analysis of Airborne Particulate Matter (PM2.5) over Hong Kong Using Remote Sensing and GIS

    PubMed Central

    Shi, Wenzhong; Wong, Man Sing; Wang, Jingzhi; Zhao, Yuanling

    2012-01-01

    Airborne fine particulates (PM2.5; particulate matter with diameter less than 2.5 μm) are receiving increasing attention for their potential toxicities and roles in visibility and health. In this study, we interpreted the behavior of PM2.5 and its correlation with meteorological parameters in Hong Kong, during 2007–2008. Significant diurnal variations of PM2.5 concentrations were observed and showed a distinctive bimodal pattern with two marked peaks during the morning and evening rush hour times, due to dense traffic. The study observed higher PM2.5 concentrations in winter when the northerly and northeasterly winds bring pollutants from the Chinese mainland, whereas southerly monsoon winds from the sea bring fresh air to the city in summer. In addition, higher concentrations of PM2.5 were observed in rush hours on weekdays compared to weekends, suggesting the influence of anthropogenic activities on fine particulate levels, e.g., traffic-related local PM2.5 emissions. To understand the spatial pattern of PM2.5 concentrations in the context of the built-up environment of Hong Kong, we utilized MODerate Resolution Imaging Spectroradiometer (MODIS) Aerosol Optical Thickness (AOT) 500 m data and visibility data to derive aerosol extinction profile, then converted to aerosol and PM2.5 vertical profiles. A Geographic Information Systems (GIS) prototype was developed to integrate atmospheric PM2.5 vertical profiles with 3D GIS data. An example of the query function in GIS prototype is given. The resulting 3D database of PM2.5 concentrations provides crucial information to air quality regulators and decision makers to comply with air quality standards and in devising control strategies. PMID:22969323

  6. Recognition of 2',5'-linked oligoadenylates by human ribonuclease L: molecular dynamics study.

    PubMed

    Maláč, Kamil; Barvík, Ivan

    2014-04-01

    The capability of current MD simulations to be used as a tool in rational design of agonists of medically interesting enzyme RNase L was tested. Dimerization and enzymatic activity of RNase L is stimulated by 2',5'-linked oligoadenylates (pA₂₅A₂₅A; 2-5A). First, it was necessary to ensure that a complex of monomeric human RNase L and 25A was stable in MD simulations. It turned out that Glu131 had to be protonated. The non-protonated Glu131 caused dissociation of 2-5A from RNase L. Because of the atypical 2'-5' internucleotide linkages and a specific spatial arrangement of the 25A trimer, when a single molecule carries all possible conformers of the glycosidic torsion angle, several versions of the AMBER force field were tested. One that best maintained functionally important interactions of 25A and RNase L was selected for subsequent MD simulations. Furthermore, we wonder whether powerful GPUs are able to produce MD trajectories long enough to convincingly demonstrate effects of subtle perturbations of interactions between 25A and RNase L. Detrimental impacts of various point mutations of RNase L (R155A, F126A, W60A, K89A) on 2-5A binding were observed on a time scale of 200 ns. Finally, 2-5A analogues with a bridged 3'--O,4'--C-alkylene linkage (B) introduced into the adenosine units (A) were used to assess ability of MD simulations to distinguish on the time scale of hundreds of nanoseconds between agonists of RNase L (pA₂₅A₂₅B, pB₂₅A₂₅A, pB₂₅A₂₅B) and inactive analogs (pA₂₅B₂₅A, pA₂₅B₂₅B, pB₂₅B₂₅A, pB₂₅B₂₅B). Agonists were potently bound to RNase L during 200 ns MD runs. For inactive 2-5A analogs, by contrast, significant disruptions of their interactions with RNase L already within 100 ns MD runs were found. PMID:24633766

  7. The socioeconomic drivers of China’s primary PM2.5 emissions

    NASA Astrophysics Data System (ADS)

    Guan, Dabo; Su, Xin; Zhang, Qiang; Peters, Glen P.; Liu, Zhu; Lei, Yu; He, Kebin

    2014-01-01

    Primary PM2.5 emissions contributed significantly to poor air quality in China. We present an interdisciplinary study to measure the magnitudes of socioeconomic factors in driving primary PM2.5 emission changes in China between 1997-2010, by using a regional emission inventory as input into an environmentally extended input-output framework and applying structural decomposition analysis. Our results show that China’s significant efficiency gains fully offset emissions growth triggered by economic growth and other drivers. Capital formation is the largest final demand category in contributing annual PM2.5 emissions, but the associated emission level is steadily declining. Exports is the only final demand category that drives emission growth between 1997-2010. The production of exports led to emissions of 638 thousand tonnes of PM2.5, half of the EU27 annual total, and six times that of Germany. Embodied emissions in Chinese exports are largely driven by consumption in OECD countries.

  8. A compact 2.5-Kelvin closed-cycle refrigerator

    NASA Technical Reports Server (NTRS)

    Britcliffe, Mike

    1990-01-01

    A helium refrigerator utilizing the Gifford-McMahon/Joule-Thomson cycle was designed and tested to demonstrate the feasibility of using small closed-cycle refrigerators as an alternative to batch filled-cryostats for operating temperatures below 4 K. The systems could be used to cool low-noise microwave maser amplifiers located in large parabolic antennas. These antennas tilt vertically, making conventional liquid-filled dewars difficult to use. The system could also be used for a nontilting beam waveguide antenna to reduce the helium consumption of a liquid helium cryostat. The prototype system is adjustable to provide 700 milliwatts of cooling at 2.5 K to 3 watts at 4.3 K. The performance of the unit is not significantly affected by operation in any physical orientation.

  9. A compact 2.5-Kelvin closed-cycle refrigerator

    NASA Astrophysics Data System (ADS)

    Britcliffe, Mike

    A helium refrigerator utilizing the Gifford-McMahon/Joule-Thomson cycle was designed and tested to demonstrate the feasibility of using small closed-cycle refrigerators as an alternative to batch filled-cryostats for operating temperatures below 4 K. The systems could be used to cool low-noise microwave maser amplifiers located in large parabolic antennas. These antennas tilt vertically, making conventional liquid-filled dewars difficult to use. The system could also be used for a nontilting beam waveguide antenna to reduce the helium consumption of a liquid helium cryostat. The prototype system is adjustable to provide 700 milliwatts of cooling at 2.5 K to 3 watts at 4.3 K. The performance of the unit is not significantly affected by operation in any physical orientation.

  10. Asymmetric transformations of achiral 2,5-cyclohexadienones

    PubMed Central

    Kalstabakken, Kyle A.; Harned, Andrew M.

    2014-01-01

    Cyclohexadienones are versatile platforms for performing asymmetric synthesis as evidenced by the numerous natural product syntheses that exploit their diverse reactivity profile. However, there are few general methods available for the direct asymmetric synthesis of chiral cyclohexadienones. To circumvent this problem, several researchers have developed catalytic asymmetric methods that employ readily available achiral 2,5-cyclohexadienones as substrates. Many of these reactions are desymmetrizations in which one of the enantiotopic alkenes of an achiral dienone is transformed. Others involve selective reaction at one alkene of an unsymmetrically substituted, achiral dienone. This review will cover advances in this area over the last 20 years and the application of these strategies in complex molecule synthesis. PMID:26688596

  11. AMBIENT PM2.5 SAMPLING AND ANALYSIS

    SciTech Connect

    Unknown

    2001-04-30

    This is the third semi-annual technical progress report summarizing observations and tentative conclusions drawn from evaluations of the data captured to date from the operation of the ambient PM{sub 2.5} speciation sites in a geographical area encompassing southeastern Ohio, western Pennsylvania, and northwestern West Virginia. The overall goal of this program, called the Upper Ohio River Valley Project (UORVP), is to better understand the relationship between coal-based power system emissions and ambient air quality in the upper Ohio River Valley region through the collection of chemically resolved or speciated data. In order to provide a ''stand alone'' document, this report contains updated versions of Section 1 (Introduction) and Section 2 (Experimental) in their entirety from the first report.

  12. Greater Sage-Grouse National Research Strategy

    USGS Publications Warehouse

    Hanser, Steven E.; Manier, Daniel J.

    2013-01-01

    The condition of the sagebrush ecosystem has been declining in the Western United States, and greater sage-grouse (Centrocercus urophasianus), a sagebrush-obligate species, has experienced concurrent decreases in distribution and population numbers. This has prompted substantial research and management over the past two decades to improve the understanding of sage-grouse and its habitats and to address the observed decreases in distribution and population numbers. The amount of research and management has increased as the year 2015 approaches, which is when the U.S. Fish and Wildlife Service (FWS) is expected to make a final decision about whether or not to protect the species under the Endangered Species Act. In 2012, the Sage-Grouse Executive Oversight Committee (EOC) of the Western Association of Fish and Wildlife Agencies (WAFWA) requested that the U.S. Geological Survey (USGS) lead the development of a Greater Sage-Grouse National Research Strategy (hereafter Research Strategy). This request was motivated by a practical need to systematically connect existing research and conservation plans with persisting or emerging information needs. Managers and researchers also wanted to reduce redundancy and help focus limited funds on the highest priority research and management issues. The USGS undertook the development of this Research Strategy, which addresses information and science relating to the greater sage-grouse and its habitat across portions of 11 Western States. This Research Strategy provides an outline of important research topics to ensure that science information gaps are identified and documented in a comprehensive manner. Further, by identifying priority topics and critical information needed for planning, research, and resource management, it provides a structure to help coordinate members of an expansive research and management community in their efforts to conduct priority research.

  13. Steady-state effects of 2,5,2',5'-tetrachlorobiphenyl on growth, photosynthesis, and P uptake in Selenastrum capricornutum

    SciTech Connect

    Rhee, G.Y.; Shane, L.; DeNucci, A.

    1988-06-01

    The steady-state effect of 2,5,2',5'-tetrachlorobiphenyl (TCBP) on the green alga selenastrum capricornutum was investigated in a P-limited two-stage chemostate system. The partition coefficient of this polychlorinated biphenyl congener was 5.9 x 10/sup 4/ in steady-state cultures. At a cellular TCBP concentration of 12.2 x 10/sup -8/ ng x cell/sup -1/, growth rate was not affected. However, photosynthetic capacity (P/sub max/) was significantly enhanced by TCBP (56 x 10/sup -9/ ..mu..mol of C x cell/sup -1/ x h/sup -1/ versus 34 x 10/sup -9/ ..mu..mol of C x cell/sup -1/ x h/sup -1/ in the control). Photosynthetic efficiency, or the slope of the photosynthesis-irradiance curve, was also significantly higher. There was little difference in the cell chlorophyll a content, and therefore the difference in these photosynthetic characteristics was the same even when they were expressed on a per-chlorophyll a basis. Cell C content was higher in TCBP-containing cells than in TCBP-free cells, but approximately 36% of the C fixed by cells with TCBP was not incorporated as cell C. The maximum P uptake rate was also enhanced by TCBP, but the half-saturation concentration appeared to be unaffected.

  14. Compressional and shear wave velocities in granular materials to 2.5 kilobars

    NASA Technical Reports Server (NTRS)

    Talwani, P.; Nur, A.; Kovach, R. L.

    1973-01-01

    The velocities of seismic compressional waves and, for the first time, shear wave velocities in silica sand, volcanic ash, and basalt powder were determined under hydrostatic confining pressures to 2.5 kb. Simultaneously, the porosity of these materials was obtained as a function of confining pressure. The presented results have important implications for the self-compaction hypothesis that has been postulated to explain the lunar near-surface seismic velocity variation.

  15. Greater auricular nerve masquerading as lymph node.

    PubMed

    Saxena, Shilpi; Deb, Prabal; Nijhawan, Vijay Shrawan; Kharayat, Veena; Verma, Rajesh

    2015-01-01

    Hansen's disease is on the verge of being eliminated from India and often missed by clinicians due to low index of suspicion. We present an unusual case in which greater auricular nerve thickening masqueraded as enlarged lymph node in the neck. The patient was referred for fine needle aspiration cytology, which revealed epithelioid cell granulomas suggestive of Hansen's disease. Further clinical examination and investigations including the skin biopsy confirmed the disease, highlighting the role of pathologist in the management of such unusual presentation of a common disease. PMID:26229249

  16. Greater auricular nerve masquerading as lymph node

    PubMed Central

    Saxena, Shilpi; Deb, Prabal; Nijhawan, Vijay Shrawan; Kharayat, Veena; Verma, Rajesh

    2015-01-01

    Hansen's disease is on the verge of being eliminated from India and often missed by clinicians due to low index of suspicion. We present an unusual case in which greater auricular nerve thickening masqueraded as enlarged lymph node in the neck. The patient was referred for fine needle aspiration cytology, which revealed epithelioid cell granulomas suggestive of Hansen's disease. Further clinical examination and investigations including the skin biopsy confirmed the disease, highlighting the role of pathologist in the management of such unusual presentation of a common disease. PMID:26229249

  17. Interspecific hybridization between greater kudu and nyala.

    PubMed

    Dalton, Desiré L; Tordiffe, Adrian; Luther, Ilse; Duran, Assumpta; van Wyk, Anna M; Brettschneider, Helene; Oosthuizen, Almero; Modiba, Catherine; Kotzé, Antoinette

    2014-06-01

    Hybridization of wildlife species, even in the absence of introgression, is of concern due to wasted reproductive effort and a reduction in productivity. In this study we detail an accidental mating between a female nyala (Tragelaphus angasii) and a male greater kudu (T. strepsiceros). The hybrid was phenotypically nyala and was identified as such based on mitochondrial DNA. Further genetic analysis based on nine microsatellite markers, chromosome number and chromosome morphology however, confirmed its status as an F1 hybrid. Results obtained from a reproductive potential assessment indicated that this animal does not have the potential to breed successfully and can be considered as sterile. PMID:24906427

  18. Continuous and filter-based measurements of PM 2.5 nitrate and sulfate at the Fresno Supersite.

    PubMed

    Chow, Judith C; Watson, John G; Lowenthal, Douglas H; Park, Kihong; Doraiswamy, Prakash; Bowers, Ken; Bode, Richard

    2008-09-01

    PM(2.5) nitrate (NO-(3)) and sulfate (SO=(4)) were measured continuously with R&P8400N and R&P8400S instruments, respectively, and compared with filter-based measurements at the Fresno Supersite from October, 2000 through December, 2005. NO-(3) concentrations were higher in winter than summer with a long-term decreasing trend. Correlations between 24-h average continuous and filter-based NO-(3) were greater than 0.96 in 4 out of 5 years. Continuous NO-(3) was generally lower than filter-based NO-(3) although the difference decreased over time, from -52% in 2001 to +13% in 2005. These differences were similar in winter (-23%) and summer (-19%) while the corresponding differences between ambient and instrument temperature were -12 and 0.7 degrees C, respectively. Neither seasonal nor long-term trends in NO-(3) can be explained by variations in ambient temperature, the difference between ambient and instrument temperature, or changes in aerosol chemical composition. There were no seasonal or long-term trends in SO=(4) concentrations, partially due to low concentrations observed in Fresno. Long-term variability in the performance of R&P8400 NO-(3) and SO=(4) instruments suggest that collocation with filter measurements is needed for long-term measurements. PMID:17929182

  19. Six lessons learned for greater success.

    PubMed

    Leander, W J

    1993-01-01

    These six lessons learned for greater success with your Patient Focused communications can help keep your cultural change process in sync with your operational change process. Of course, there are other key elements of the former, including: formal Patient Focused educational programs; restructured Human Resources "systems" (e.g., job descriptions and compensation programs); and migration toward greater organizational empowerment and more self-directed work teams. Still, your Patient Focused communications campaign will spearhead the cultural change process. As such, it will have the opportunity to make the very first impact. Basically, your communications can make or break your Patient Focused Care program from Day One. It's up to you--learn the lessons learned by others and your organization may follow the words of Marx rather than those of Brand: "Workers of the world, unite (on behalf of your Patient Focused Care program)!" Karl Marx.p6 "Workers of the world, fan out (in formation against your Patient Focused Care program)!" Stewart Brand. PMID:10133393

  20. Differences in allergic inflammatory responses between urban PM2.5 and fine particle derived from desert-dust in murine lungs.

    PubMed

    He, Miao; Ichinose, Takamichi; Kobayashi, Makoto; Arashidani, Keiichi; Yoshida, Seiichi; Nishikawa, Masataka; Takano, Hirohisa; Sun, Guifan; Shibamoto, Takayuki

    2016-04-15

    The biological and chemical natures of materials adsorbed onto fine particulate matter (PM2.5) vary by origin and passage routes. The exacerbating effects of the two samples-urban PM2.5 (U-PM2.5) collected during the hazy weather in a Chinese city and fine particles (ASD-PM2.5) collected during Asian sand dust (ASD) storm event days in Japan-on murine lung eosinophilia were compared to clarify the role of toxic materials in PM2.5. The amounts of β-glucan and mineral components were higher in ASD-PM2.5 than in U-PM2.5. On the other hand, organic chemicals, including polycyclic aromatic hydrocarbons (PAHs), were higher in U-PM2.5 than in ASD-PM2.5. When BALB/c mice were intratracheally instilled with U-PM2.5 and ASD-PM2.5 (total 0.4 mg/mouse) with or without ovalbumin (OVA), various biological effects were observed, including enhancement of eosinophil recruitment induced by OVA in the submucosa of the airway, goblet cell proliferation in the bronchial epithelium, synergic increase of OVA-induced eosinophil-relevant cytokines and a chemokine in bronchoalveolar lavage fluid, and increase of serum OVA-specific IgG1 and IgE. Data demonstrate that U-PM2.5 and ASD-PM2.5 induced allergic inflammatory changes and caused lung pathology. U-PM2.5 and ASD-PM2.5 increased F4/80(+) CD11b(+) cells, indicating that an influx of inflammatory and exudative macrophages in lung tissue had occurred. The ratio of CD206 positive F4/80(+) CD11b(+) cells (M2 macrophages) in lung tissue was higher in the OVA+ASD-PM2.5 treated mice than in the OVA+U-PM2.5 treated mice. These results suggest that the lung eosinophilia exacerbated by both PM2.5 is due to activation of a Th2-associated immune response along with induced M2 macrophages and the exacerbating effect is greater in microbial element (β-glucan)-rich ASD-PM2.5 than in organic chemical-rich U-PM2.5. PMID:26917405

  1. Comparisons of urban and rural PM10-2.5 and PM2.5 mass concentrations and semi-volatile fractions in northeastern Colorado

    NASA Astrophysics Data System (ADS)

    Clements, Nicholas; Hannigan, Michael P.; Miller, Shelly L.; Peel, Jennifer L.; Milford, Jana B.

    2016-06-01

    Coarse (PM10-2.5) and fine (PM2.5) particulate matter in the atmosphere adversely affect human health and influence climate. While PM2.5 is relatively well studied, less is known about the sources and fate of PM10-2.5. The Colorado Coarse Rural-Urban Sources and Health (CCRUSH) study measured PM10-2.5 and PM2.5 mass concentrations, as well as the fraction of semi-volatile material (SVM) in each size regime (SVM2.5, SVM10-2.5), from 2009 to early 2012 in Denver and comparatively rural Greeley, Colorado. Agricultural operations east of Greeley appear to have contributed to the peak PM10-2.5 concentrations there, but concentrations were generally lower in Greeley than in Denver. Traffic-influenced sites in Denver had PM10-2.5 concentrations that averaged from 14.6 to 19.7 µg m-3 and mean PM10-2.5 / PM10 ratios of 0.56 to 0.70, higher than at residential sites in Denver or Greeley. PM10-2.5 concentrations were more temporally variable than PM2.5 concentrations. Concentrations of the two pollutants were not correlated. Spatial correlations of daily averaged PM10-2.5 concentrations ranged from 0.59 to 0.62 for pairs of sites in Denver and from 0.47 to 0.70 between Denver and Greeley. Compared to PM10-2.5, concentrations of PM2.5 were more correlated across sites within Denver and less correlated between Denver and Greeley. PM10-2.5 concentrations were highest during the summer and early fall, while PM2.5 and SVM2.5 concentrations peaked in winter during periodic multi-day inversions. SVM10-2.5 concentrations were low at all sites. Diurnal peaks in PM10-2.5 and PM2.5 concentrations corresponded to morning and afternoon peaks of traffic activity, and were enhanced by boundary layer dynamics. SVM2.5 concentrations peaked around noon on both weekdays and weekends. PM10-2.5 concentrations at sites located near highways generally increased with wind speeds above about 3 m s-1. Little wind speed dependence was observed for the residential sites in Denver and Greeley. The mass

  2. Time?

    NASA Astrophysics Data System (ADS)

    Amoroso, Richard L.

    2013-09-01

    The concept of time in the `clockwork' Newtonian world was irrelevant; and has generally been ignored until recently by several generations of physicists since the implementation of quantum mechanics. We will set aside the utility of time as a property relating to physical calculations of events relating to a metrics line element or as an aspect of the transformation of a particles motion/interaction in a coordinate system or in relation to thermodynamics etc., i.e. we will discard all the usual uses of time as a concept used to circularly define physical parameters in terms of other physical parameters; concentrating instead on time as an aspect of the fundamental cosmic topology of our virtual reality especially as it inseparably relates to the nature and role of the observer in natural science.

  3. Indoor PM2.5 in Santiago, Chile, spring 2012: Source apportionment and outdoor contributions

    NASA Astrophysics Data System (ADS)

    Barraza, Francisco; Jorquera, Héctor; Valdivia, Gonzalo; Montoya, Lupita D.

    2014-09-01

    Indoor and outdoor PM2.5 sampling campaigns were carried out at Santiago, Chile (6 million inhabitants, 33.5°S, 70.6°W) in spring 2012. A pair of samplers was placed inside each household studied and an additional pair of samplers was placed at a fixed outdoor location for measuring trace elements and elemental (EC) and organic carbon (OC) in Teflon and quartz filters, respectively. A total of 47 households in downtown Santiago were included in this study. Mean outdoor and indoor PM2.5 concentrations were 19.2 and 21.6 μg/m3, respectively. Indoor concentrations of PM2.5 were affected by socioeconomic status (p = 0.048) but no such evidence was found for PM2.5 species, except lead (p = 0.046). Estimated species infiltration factors were 0.70 (±0.19), 0.98 (±0.21), 0.80 (±0.12) and 0.80 (±0.03) for PM2.5, OC, EC and sulfur, respectively. Estimated household infiltration factors had a median of 0.75, mean of 0.78, standard deviation of 0.18 and interquartile range (IQR) 0.67-0.86. For the very first time, Positive Matrix Factorization (PMF3) was applied to an indoor PM2.5 chemical composition data set measured at Santiago. Source identification was carried out by inspection of key species and by comparison with published source profiles; six sources were identified. Three of them were outdoor contributions: motor vehicles with 5.6 (±0.7) μg/m3, street dust with 2.9 (±0.5) μg/m3 and secondary sulfates with 3.4 (±0.5) μg/m3. The indoor sources were: indoor dust with 1.6 (±0.3) μg/m3, cleaning and cooking with 2.3 (±0.3) μg/m3 and cooking and environmental tobacco smoke with 6.1 (±0.7) μg/m3. There is potential for further reducing PM2.5 population exposure in the short term -by improving ventilation of indoor air and controlling indoor sources - and in the long term - with filtration of outdoor air and household improvements to reduce air change rates.

  4. The distribution of PM10 and PM2.5 carbonaceous aerosol in Baotou, China

    NASA Astrophysics Data System (ADS)

    Zhou, Haijun; He, Jiang; Zhao, Boyi; Zhang, Lijun; Fan, Qingyun; Lü, Changwei; Dudagula; Liu, Tao; Yuan, Yinghui

    2016-09-01

    Particulate matter (PM), including PM10 and PM2.5, is one of the major impacts on air quality, visibility, climate change, earth radiation balance, and public health. Organic carbon (OC) and elemental carbon (EC) are the major components of PM. 804 samples (PM10 and PM2.5) were simultaneously collected from six urban sites covering 3 districts in Baotou, in January, April, September, and November 2014. As to a long-term study on the effects of carbonaceous aerosol, data were collected annually at Environmental Protection Agency of Baotou (EPB). The concentrations of PM10 and PM2.5, the spatial distribution and content of OC and EC, the relationship between OC and EC, and the formation of secondary organic carbon (SOC) have been investigated. The findings indicated that the concentrations of these particle matter are higher than that in US or European standards. The average concentrations of OC in PM10 and PM2.5 follow the order: January > November > April > September; and for EC in PM10 and PM2.5 follow the order: January > November > September > April. Affected by metrological factors, it was indicated that high wind speed and low relative humidity were beneficial for removal of OC and EC in January and November. Pearson correlations and cluster analysis on OC and EC concentrations in PM10 and PM2.5 with gaseous pollutants (SO2, NO2, and CO) suggested that OC shared the same emission sources with SO2 and CO from combustion, while EC's sources mainly came from vehicles exhaust and combustion which contributed to NO2 as well. The OC concentration is mainly primary in warm months, while it appears secondary in cold months in Baotou. There is a common characteristic among the cities with higher SOC in winter, wherever the coal combustion can lead to the severe pollution. This work is important for the construction of the database of OC and EC concentrations in PM10 and PM2.5 at spatial and time intervals, and it can provide scientific suggestion for similar PM

  5. Bidirectional reflectance measurement of zinc oxide in 0.25 to 2.5 microns spectrum

    NASA Technical Reports Server (NTRS)

    Scott, R. L., Jr.

    1974-01-01

    An experimental apparatus was designed and used to measure the bidirectional reflectance of zinc oxide in the spectrum 0.25 to 2.5 microns. The nonspecular reflectance is essentially Lambert for wavelengths above 0.40 microns with the most deviation occuring for large source zenith angles. Below 0.400 microns the nonspecular reflectance is greater than Lambert in all directions and is greatest in the forward and backscatter directions. The ratio of the specular component to the nonspecular component at a zenith of 0 degrees was found to increase with source zenith and wavelength for wavelengths above 0.400 microns. Below 0.400 microns this ratio increases as wavelengths decrease. The variation of bidirectional reflectance with wavelength was found to have the characteristics absorption for Zn0 for wavelength below 0.400 microns.

  6. Planning for greater-confinement disposal

    SciTech Connect

    Gilbert, T.L.; Luner, C.; Meshkov, N.K.; Trevorrow, L.E.; Yu, C.

    1984-01-01

    This contribution is a progress report for preparation of a document that will summarize procedures and technical information needed to plan for and implement greater-confinement disposal (GCD) of low-level radioactive waste. Selection of a site and a facility design (Phase I), and construction, operation, and extended care (Phase II) will be covered in the document. This progress report is limited to Phase I. Phase I includes determination of the need for GCD, design alternatives, and selection of a site and facility design. Alternative designs considered are augered shafts, deep trenches, engineered structures, high-integrity containers, hydrofracture, and improved waste form. Design considerations and specifications, performance elements, cost elements, and comparative advantages and disadvantages of the different designs are covered. Procedures are discussed for establishing overall performance objectives and waste-acceptance criteria, and for comparative assessment of the performance and cost of the different alternatives. 16 references.

  7. Greater confinement disposal of radioactive wastes

    SciTech Connect

    Trevorrow, L.E.; Gilbert, T.L.; Luner, C.; Merry-Libby, P.A.; Meshkov, N.K.; Yu, C.

    1985-01-01

    Low-level radioactive waste (LLW) includes a broad spectrum of different radionuclide concentrations, half-lives, and hazards. Standard shallow-land burial practice can provide adequate protection of public health and safety for most LLW. A small volume fraction (approx. 1%) containing most of the activity inventory (approx. 90%) requires specific measures known as greater-confinement disposal (GCD). Different site characteristics and different waste characteristics - such as high radionuclide concentrations, long radionuclide half-lives, high radionuclide mobility, and physical or chemical characteristics that present exceptional hazards - lead to different GCD facility design requirements. Facility design alternatives considered for GCD include the augered shaft, deep trench, engineered structure, hydrofracture, improved waste form, and high-integrity container. Selection of an appropriate design must also consider the interplay between basic risk limits for protection of public health and safety, performance characteristics and objectives, costs, waste-acceptance criteria, waste characteristics, and site characteristics.

  8. Planning for greater-confinement disposal

    NASA Astrophysics Data System (ADS)

    Gilbert, T. L.; Luner, C.; Meshkov, N. K.; Trevorrow, L. E.; Yu, C.

    The preparation of a document that will summarize procedures and technical information needed to plan for and implement greater-confinement disposal (CGD) of low-level radioactive waste is presented. Selection of a site and a facility design (Phase I), and construction, operation, and extended care (Phase II) will be covered in the document. Phase I includes determination of the need for GCD, design alternatives, and selection of a site and facility design. Alternative designs considered are augered shafts, deep trenches, engineered structures, high-integrity containers, hydrofracture, and improved waste form. Design considerations and specifications, performance elements, cost elements, and comparative advantages and disadvantages of the different designs are covered. Procedures are discussed for establishing overall performance objectives and waste-acceptance criteria, and for comparative assessment of the performance and cost of the different alternatives.

  9. Health and Greater Manchester in Historical Perspective

    PubMed Central

    Snow, Stephanie J.

    2015-01-01

    This article maps the history of health organisation across Greater Manchester (GM), primarily since the Second World War, to show how against a continuing backdrop of health inequalities, services have been driven (and constrained) by the needs and the politics of each period. Defining ‘success’ as benefits for patients the article identifies examples such as Salford’s mental health services (1950s and 1960s), public health in North Manchester (1970s and 1980s), the creation of centres for diabetes, sickle-cell and thalassaemia (1980s) and the formation of the Joint Health Unit in 2002. What this history shows is that over the period the common factors influencing the ‘success’ of health organisation across GM have been the championing of particular issues by multi-disciplinary groups working across health and social care and stability in structures and personnel. PMID:27499557

  10. Exposure to PM2.5 in modern office buildings through elemental characterization and oxidative potential

    NASA Astrophysics Data System (ADS)

    Szigeti, Tamás; Kertész, Zsófia; Dunster, Christina; Kelly, Frank J.; Záray, Gyula; Mihucz, Victor G.

    2014-09-01

    Fifty samples of indoor and outdoor PM2.5 were collected onto quartz fiber and Teflon membrane filters in five office buildings equipped with heating, ventilation and air-conditioning system for 8 h daily in order to coincide with the work shift of employees. Samples were analyzed for i) mass concentration; ii) elemental concentration; and iii) oxidative potential (OP) through antioxidant depletion. The PM2.5 mass concentration exceeded the annual mean guideline of 10 μg m-3 WHO in 50% of the samples. Indoor and outdoor PM2.5 mass concentrations correlated almost linearly. Proton-induced X-ray emission (PIXE) spectrometry was used for the monitoring of 21 elements. Quantitative determination was achieved in the case of Teflon filters only for Al, Si, S, Cl, K, Ca, Ti, Cr, Mn, Fe and Zn at ng m-3 concentration level. Quartz fiber filters were less adequate for the PIXE measurements due to their greater thickness and filamentary structure. Ca, Cr, Zn and Ti had generally higher concentration (mg g-1) indoors. Indoor/outdoor (I/O) OP values were higher than one in 14% and 57% of the samples in the case of ascorbate and reduced glutathione (GSH), respectively. Spatial and temporal variations of OP were observed across the office buildings. The I/O ratios for OP, Cr and Zn concentrations in the case of GSH were higher for three buildings. Significant relationship was observed between GSH oxidation and Cr and Zn concentrations. Thus, employees were exposed to a higher extent to reactive oxygen species in three buildings.

  11. Acute airway narrowing in monkeys from challenge with 2. 5 ppm formaldehyde generated from formalin

    SciTech Connect

    Biagini, R.E.; Moorman, W.J.; Knecht, E.A.; Clark, J.C. ); Bernstein, I.L. )

    1988-10-01

    Nine adult male Cynomolgus monkeys (Macaca fascicularis) were exposed for 10 min to 2.55 {plus minus} 0.03 ppm formaldehyde (HCHO; mean {plus minus} standard error of the mean, SEM) generated from formalin with a newly developed HCHO challenge system. The generation system was capable of producing highly stable HCHO vapor concentrations with fluctuations of HCHO concentrations of less than {plus minus} 5%. The experimental design included pre-exposure methacholine challenge to determine if responses to HCHO were associated with pre-existing bronchial hyperreactivity. Significant changes in average pulmonary flow resistance (R{sub L}) were observed (compared to control R{sub L} values) at 2, 5, and 10 min post-HCHO challenge. Pre-challenge R{sub L} values (mean {plus minus} SEM) were 11,3 {plus minus} 1,4 cm H{sub 2}O {center dot} l/s, while at 2, 5, and 10 min after HCHO challenge, values were 16,1 {plus minus} 2,1, 16,9 {plus minus} 2,8, and 20,0 {plus minus} 3,4 cm H{sub 2}O {center dot} l/s, respectively. Methacholine challenge data suggest that reactions to HCHO tend to be greater in monkeys hyperreactive to methacholine, but the relationship does not reach statistical significance in this small series of animals. These data indicate that significant pulmonary function deficits occur immediately after challenge with 2.55 ppm HCHO vapor in monkeys.

  12. Mechanism of charge transport in poly(2,5-dimethoxyaniline)

    NASA Astrophysics Data System (ADS)

    Singh, Rajiv K.; Kumar, Amit; Singh, Ramadhar

    2010-06-01

    Poly(2,5-dimethoxyaniline) (PDMA) has been synthesized by chemical oxidative polymerization technique using varying ratio of oxidants; ferric chloride (FeCl3) and ammonium persulfate [(NH4)2S2O8], in an inert atmosphere at low temperature ˜278 K. The synthesized samples of PDMA have been characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and by measuring its dc conductivity (σdc). The temperature dependence of dc conductivity of PDMA samples has been examined in the wide temperature range 6-303 K. The analysis of dc conductivity data reveals that in the temperature range ˜100-303 K, the dc conductivity is predominantly governed by Mott's three-dimensional variable range hopping, however, below 100 K tunneling seems to dominate. Different Mott's parameters such as characteristic temperature (T0), density of states at the Fermi level [N(EF)], the average hopping distance (R ), and the average hopping energy (W) have been estimated for all the PDMA samples and are in good agreement with the values reported earlier for other conjugated polymers.

  13. A 2.5m astronomical telescope project

    NASA Astrophysics Data System (ADS)

    Phaichith, Oudomsanith

    2008-07-01

    The paper reports a recently started project for a 2,5 meter diameter robotic telescope dedicated to astronomy and education for the University of Moscow's Sternberg Institute. As a prime contractor Sagem Defense Securite's REOSC department will take on the program design as well as the production of the optical components. The project includes the Alt-Az mount, the dome and its cooling and air stabilization system, the weather station, the high-resolution camera and realization, transport and installation on-site at the Kislovodsk solar station located in the Caucasus mountains as well as the initial training for the operators. The telescope will provide a wide field of view of 40 arcmin at the Cassegrain F/8 focus. An escapable and rotating tertiary mirror will allow to direct the light to the two Nasmyth foci and two student ports located at 90° from the Nasmyth foci. A 4k x 4k CCD camera cryogenically cooled to 140 K will be provided as a first light camera. All will be delivered by end 2009. Remotely controlled via the internet, the telescope will allow Russia to train doctors in astronomy, participate in international research projects and draw up the future specifications of a larger and more advanced telescope.

  14. Calibrating a ground-based backscatter lidar for continuous measurements of PM2.5

    NASA Astrophysics Data System (ADS)

    Pesch, Markus; Oderbolz, Daniel

    2007-10-01

    One of the main issues of atmospheric research and air quality control is the reduction of harmful particulate matter (PM) in the atmosphere. Small particles can enter the human airways and cause serious health problems such as COPD (Chronic Obstructive Pulmonary Disease), asthma or even lung cancer. Recently, interest has shifted from PM10 to finer fractions of particulate matter, e.g. PM2.5, because the health impact of finer particles is considered to be more severe. Up to now measurements of particulate matter were carried out mainly at ground level. However important atmospheric processes, i.e. particle formation, transport and vertical mixing processes, take place predominantly at higher altitudes in the planetary boundary layer. Lidar in principle provides the ability to observe these processes where they occur. The new method outlined in this paper demonstrates the use of a small sized and quite inexpensive lidar in stand-alone operation to investigate transport processes of particulate matter, and PM2.5 in particular. Continuous measurements of PM2.5 as a reference are gained with a conventional in-situ monitor, installed on a tower at an altitude of 325 m in the North of Berlin (Frohnauer Turm). These PM2.5 measurements will be compared with backscatter Lidar data (1064 nm) taken from approx. 60 m over ground up to an altitude of 15 km with a spatial resolution of 15 m. The vertical backscatter profiles at 325 m will be correlated to the concentrations obtained by the PM2,5 monitor on the tower. Both measurements have a time resolution of 180 s to observe also processes that take place at short time scales. The objective is to gain correlation functions for estimating PM2.5 concentrations from backscatter Lidar data. Such a calibrated Lidar system is a valuable instrument for environmental agencies and atmospheric research groups to observe and investigate causes of high level PM concentrations. First results show a reasonably good linear correlation

  15. Characterization and evaluation of 2.5 MV electronic portal imaging for accurate localization of intra- and extracranial stereotactic radiosurgery.

    PubMed

    Song, Kwang Hyun; Snyder, Karen Chin; Kim, Jinkoo; Li, Haisen; Ning, Wen; Rusnac, Robert; Jackson, Paul; Gordon, James; Siddiqui, Salim M; Chetty, Indrin J

    2016-01-01

    2.5 MV electronic portal imaging, available on Varian TrueBeam machines, was characterized using various phantoms in this study. Its low-contrast detectability, spatial resolution, and contrast-to-noise ratio (CNR) were compared with those of conventional 6 MV and kV planar imaging. Scatter effect in large patient body was simulated by adding solid water slabs along the beam path. The 2.5 MV imaging mode was also evaluated using clinically acquired images from 24 patients for the sites of brain, head and neck, lung, and abdomen. With respect to 6 MV, the 2.5 MV achieved higher contrast and preserved sharpness on bony structures with only half of the imaging dose. The quality of 2.5 MV imaging was comparable to that of kV imaging when the lateral separation of patient was greater than 38 cm, while the kV image quality degraded rapidly as patient separation increased. Based on the results of patient images, 2.5 MV imaging was better for cranial and extracranial SRS than the 6 MV imaging. PMID:27455505

  16. 40 CFR Table C-4 to Subpart C of... - Test Specifications for PM10, PM2.5 and PM10-2.5 Candidate Equivalent Methods

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Test Specifications for PM10, PM2.5 and... Pt. 53, Subpt. C, Table C-4 Table C-4 to Subpart C of Part 53—Test Specifications for PM10, PM2.5 and PM10-2.5 Candidate Equivalent Methods Specification PM10 PM2.5 Class I Class II Class III...

  17. Hydroxyl Radical Generation from Environmentally Persistent Free Radicals (EPFRs) in PM2.5

    PubMed Central

    Gehling, William; Khachatryan, Lavrent; Dellinger, Barry

    2015-01-01

    Hydroxyl radicals were generated from an aqueous suspension of ambient PM2.5 and detected utilizing 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trap coupled with electron paramagnetic resonance (EPR) spectroscopy. Results from this study suggested the importance of environmentally persistent free radicals (EPFRs) in PM2.5 to generate significant levels of ·OH without the addition of H2O2. Particles for which the EPFRs were allowed to decay over time induced less hydroxyl radical. Additionally, higher particle concentrations produced more hydroxyl radical. Some samples did not alter hydroxyl radical generation when the solution was purged by air. This is ascribed to internal, rather than external surface associated EPFRs. PMID:24004313

  18. Compilation and application of a primary PM 2.5 emissions inventory with high sectoral resolution in Japan

    NASA Astrophysics Data System (ADS)

    Sugiyama, Toshiharu; Nansai, Keisuke; Tohno, Susumu; Yamamoto, Kouhei

    To elucidate the macro-structure of the PM 2.5 emissions generated by Japan's economic activities, this paper presents an emission inventory of primary particles of PM 2.5 with high sectoral resolution based on the Japanese Input-Output Tables, comprising some 400 sectors. These primary PM 2.5 emissions were estimated by multiplying the estimated energy consumption associated with each fuel type by a PM 10 emission factor incorporating the technological level of dust collection in each sector and the mass ratio of PM 2.5 to PM 10. Non-energy emissions from agricultural open burning were also determined. Total PM 2.5 emissions in 2000 were 252 kt, 49% of which were due to mobile emission sources. Changes in total PM 2.5 emissions between 1990 and 2000 were also calculated. This showed that a substantial increase in energy sector emissions due to rising coal consumption was offset by a sharp decline in emissions from road vehicles and shipping vessels, resulting in an overall decrease in total emissions. In addition, the emissions induced by economic demand in each sector were quantified by means of input-output analysis, which revealed that demand for construction, foods and communications and services constituted the principal causes of real domestic emissions. An assessment of sectoral contributions to PM 2.5 emissions that takes into account the effects of human exposure, expressed as external costs, suggests that the contribution of transportation is greater than indicated on the grounds of direct emissions alone.

  19. Meteorological Modes of Variability for Fine Particulate Matter (PM2.5) Air Quality in the United States: Implications for PM2.5 Sensitivity to Climate Change

    EPA Science Inventory

    We applied a multiple linear regression model to understand the relationships of PM2.5 with meteorological variables in the contiguous US and from there to infer the sensitivity of PM2.5 to climate change. We used 2004-2008 PM2.5 observations fro...

  20. Lagged PM2.5 effects in mortality time series: Critical impact of covariate model

    EPA Science Inventory

    The two most common approaches to modeling the effects of air pollution on mortality are the Harvard and the Johns Hopkins (NMMAPS) approaches. These two approaches, which use different sets of covariates, result in dissimilar estimates of the effect of lagged fine particulate ma...

  1. INTEGRATED AND REAL-TIME DIFFUSION DENUDER SAMPLE FOR PM2.5. (R825367)

    EPA Science Inventory

    Abstract

    Particulate matter (PM) is a complex mixture of stable condensed phases, adsorbed or dissolved gases, and semi-volatile materials, i.e. compounds that transfer between the gas and condensed phases. Fine particles in both rural and urban environments contain su...

  2. Modeling of In-vehicle PM2.5 Exposure Using the Stochastic Human Exposure and Dose Simulation Model

    PubMed Central

    Liu, Xiaozhen; Frey, H. Christopher; Cao, Ye; Deshpande, Bela

    2010-01-01

    Factors that influence in-vehicle PM2.5 exposure are indentified and assessed. The methodology used in the current version of Stochastic Exposure and Dose Simulation model for Particulate Matter (SHEDS-PM) for in-vehicle PM2.5 concentration is reviewed, and alternative modeling approaches are identified and evaluated. SHEDS-PM uses a linear regression model to estimate in-vehicle PM2.5 concentration based on ambient PM2.5 concentration, such as from a fixed site monitor (FSM) or a grid cell average concentration estimate from an air quality model. The ratio of in-vehicle to FSM concentration varies substantially with respect to location, vehicle type and other factors. SHEDS-PM was used to estimate PM2.5 exposure for 1% of people living in Wake County, NC in order to assess the importance of in-vehicle exposures. In-vehicle PM2.5 exposure can be as much as half of the total exposure for some individuals, depending on employment status and the time spent in-vehicle during commuting. An alternative modeling approach is explored based on the use of a dispersion model to estimate near-road PM2.5 concentration based on FSM data and a mass balance model for estimating in-vehicle concentration. Recommendations for updating the input data to the existing model, and implementation of the alternative modeling approach are made. PMID:21209848

  3. An LUR/BME framework to estimate PM2.5 explained by on road mobile and stationary sources.

    PubMed

    Reyes, Jeanette M; Serre, Marc L

    2014-01-01

    Knowledge of particulate matter concentrations <2.5 μm in diameter (PM2.5) across the United States is limited due to sparse monitoring across space and time. Epidemiological studies need accurate exposure estimates in order to properly investigate potential morbidity and mortality. Previous works have used geostatistics and land use regression (LUR) separately to quantify exposure. This work combines both methods by incorporating a large area variability LUR model that accounts for on road mobile emissions and stationary source emissions along with data that take into account incompleteness of PM2.5 monitors into the modern geostatistical Bayesian Maximum Entropy (BME) framework to estimate PM2.5 across the United States from 1999 to 2009. A cross-validation was done to determine the improvement of the estimate due to the LUR incorporation into BME. These results were applied to known diseases to determine predicted mortality coming from total PM2.5 as well as PM2.5 explained by major contributing sources. This method showed a mean squared error reduction of over 21.89% oversimple kriging. PM2.5 explained by on road mobile emissions and stationary emissions contributed to nearly 568,090 and 306,316 deaths, respectively, across the United States from 1999 to 2007. PMID:24387222

  4. An LUR/BME Framework to Estimate PM2.5 Explained by on Road Mobile and Stationary Sources

    PubMed Central

    2015-01-01

    Knowledge of particulate matter concentrations <2.5 μm in diameter (PM2.5) across the United States is limited due to sparse monitoring across space and time. Epidemiological studies need accurate exposure estimates in order to properly investigate potential morbidity and mortality. Previous works have used geostatistics and land use regression (LUR) separately to quantify exposure. This work combines both methods by incorporating a large area variability LUR model that accounts for on road mobile emissions and stationary source emissions along with data that take into account incompleteness of PM2.5 monitors into the modern geostatistical Bayesian Maximum Entropy (BME) framework to estimate PM2.5 across the United States from 1999 to 2009. A cross-validation was done to determine the improvement of the estimate due to the LUR incorporation into BME. These results were applied to known diseases to determine predicted mortality coming from total PM2.5 as well as PM2.5 explained by major contributing sources. This method showed a mean squared error reduction of over 21.89% oversimple kriging. PM2.5 explained by on road mobile emissions and stationary emissions contributed to nearly 568 090 and 306 316 deaths, respectively, across the United States from 1999 to 2007. PMID:24387222

  5. Sandia Advanced MEMS Design Tools, Version 2.2.5

    2010-01-19

    The Sandia National Laboratories Advanced MEMS Design Tools, Version 2.2.5, is a collection of menus, prototype drawings, and executables that provide significant productivity enhancements when using AutoCAD to design MEMS components. This release is designed for AutoCAD 2000i, 2002, or 2004 and is supported under Windows NT 4.0, Windows 2000, or XP. SUMMiT V (Sandia Ultra planar Multi level MEMS Technology) is a 5 level surface micromachine fabrication technology, which customers internal and external tomore » Sandia can access to fabricate prototype MEMS devices. This CD contains an integrated set of electronic files that: a) Describe the SUMMiT V fabrication process b) Facilitate the process of designing MEMS with the SUMMiT process (prototype file, Design Rule Checker, Standard Parts Library) New features in this version: AutoCAD 2004 support has been added. SafeExplode ? a new feature that explodes blocks without affecting polylines (avoids exploding polylines into objects that are ignored by the DRC and Visualization tools). Layer control menu ? a pull-down menu for selecting layers to isolate, freeze, or thaw. Updated tools: A check has been added to catch invalid block names. DRC features: Added username/password validation, added a method to update the user?s password. SNL_DRC_WIDTH ? a value to control the width of the DRC error lines. SNL_BIAS_VALUE ? a value use to offset selected geometry SNL_PROCESS_NAME ? a value to specify the process name Documentation changes: The documentation has been updated to include the new features. While there exist some files on the CD that are used in conjunction with software package AutoCAD, these files are not intended for use independent of the CD. Note that the customer must purchase his/her own copy of AutoCAD to use with these files.« less

  6. Sandia Advanced MEMS Design Tools, Version 2.2.5

    SciTech Connect

    Yarberry, Victor; Allen, James; Lantz, Jeffery; Priddy, Brian; & Westling, Belinda

    2010-01-19

    The Sandia National Laboratories Advanced MEMS Design Tools, Version 2.2.5, is a collection of menus, prototype drawings, and executables that provide significant productivity enhancements when using AutoCAD to design MEMS components. This release is designed for AutoCAD 2000i, 2002, or 2004 and is supported under Windows NT 4.0, Windows 2000, or XP. SUMMiT V (Sandia Ultra planar Multi level MEMS Technology) is a 5 level surface micromachine fabrication technology, which customers internal and external to Sandia can access to fabricate prototype MEMS devices. This CD contains an integrated set of electronic files that: a) Describe the SUMMiT V fabrication process b) Facilitate the process of designing MEMS with the SUMMiT process (prototype file, Design Rule Checker, Standard Parts Library) New features in this version: AutoCAD 2004 support has been added. SafeExplode ? a new feature that explodes blocks without affecting polylines (avoids exploding polylines into objects that are ignored by the DRC and Visualization tools). Layer control menu ? a pull-down menu for selecting layers to isolate, freeze, or thaw. Updated tools: A check has been added to catch invalid block names. DRC features: Added username/password validation, added a method to update the user?s password. SNL_DRC_WIDTH ? a value to control the width of the DRC error lines. SNL_BIAS_VALUE ? a value use to offset selected geometry SNL_PROCESS_NAME ? a value to specify the process name Documentation changes: The documentation has been updated to include the new features. While there exist some files on the CD that are used in conjunction with software package AutoCAD, these files are not intended for use independent of the CD. Note that the customer must purchase his/her own copy of AutoCAD to use with these files.

  7. AF-GEOSpace Version 2.5: Space Environment Software

    NASA Astrophysics Data System (ADS)

    Hilmer, R. V.; Hall, T.; Roth, C.; Ling, A.; Ginet, G. P.; Madden, D.

    2010-12-01

    AF-GEOSpace is a graphics-intensive software program with space environment models and applications developed by the Space Weather Center of Excellence at AFRL. The software addresses a wide range of physical domains, e.g., solar disturbance propagation, geomagnetic field and radiation belt configurations, auroral particle precipitation, and ionospheric scintillation. AF-GEOSpace has become a platform for developing and prototyping space weather visualization products. The new AF-GEOSpace Version 2.5 (release scheduled for 2010) expands on the content of Version 2.1 by including modules addressing the following new topics: (1) energetic proton maps for the South Atlantic Anomaly (from Ginet et al. [2007]), (2) GPS scintillation outage simulation tools, (3) magnetopause location determination (Shue et al. [1998]), (4) a plasmasphere model (Global Core Plasma Model, 2009 version based on Gallagher et al. [2000]), (5) a standard ionospheric model (International Reference Ionosphere 2007), (6) the CAMMICE/MICS model of inner magnetosphere plasma population (based on Roeder et al. [2005]), (7) magnetic field models (e.g., Tsyganenko and Sitnov [2005]), and (8) loading and displaying externally-produced 3D gridded data sets within AF-GEOSpace. Improvements to existing Version 2.1 capabilities include: (1) a 2005 update to the geomagnetic cutoff rigidity model of Smart and Shea [2003], (2) a 2005 update to the ionospheric scintillation Wide-Band Model (WBMOD) of Secan and Bussey [1994], and (3) improved magnetic field flux mapping options for the existing set of AF-GEOSpace radiation belt models. A basic review of these new AF-GEOSpace capabilities will be provided. To obtain a copy of the software, please contact the first author.

  8. Malaria situation in the Greater Mekong Subregion.

    PubMed

    Hewitt, Sean; Delacollette, Charles; Chavez, Irwin

    2013-01-01

    The epidemiology of malaria in the Greater Mekong Subregion is complex and rapidly evolving. Malaria control and elimination efforts face a daunting array of challenges including multidrug-resistant parasites. This review presents secondary data collected by the national malaria control programs in the six countries between 1998 and 2010 and examines trends over the last decade. This data has a number of limitations: it is derived exclusively from public sector health facilities; falciparum-specific and then pan-specific rapid diagnostic tests were introduced during the period under review; and, recently there has been a massive increase in case detection capability as a result of increased funding. It therefore requires cautious interpretation. A series of maps are presented showing trends in incidence, mortality and proportion of cases caused by Plasmodium falciparum over the last decade. A brief overview of institutional and implementation arrangements, historical background, demographics and key issues affecting malaria epidemiology is provided for each country. National malaria statistics for 2010 are presented and their robustness discussed in terms of the public sector's share of cases and other influencing factors such as inter-country variations in risk stratification, changes in diagnostic approach and immigration. Targets are presented for malaria control and where appropriate for elimination. Each country's artemisinin resistance status is described. The epidemiological trends presented reflect the improvement in the malaria situation, however the true malaria burden is as yet unknown. There is a need for continuing strengthening and updating of surveillance and response systems. PMID:24159830

  9. Early tectonic history of the Greater Antilles

    SciTech Connect

    Lewis, J.F.; Draper, G.; Mattson, P.

    1985-01-01

    The islands of the Greater Antilles exhibit differing pre-Oligocene tectonic styles and histories, but all display the results of convergent plate activity from the Early Cretaceous to the Middle Eocene. Western and central Cuba consist of autochthonous, Jurassic and older continental crust, which was overthrust by Cretaceous ophiolites in the Early to Middle Eocene. In contrast, eastern Cuba seems to be similar to Northern Hispaniola, and both areas consist of complexes of upper Cretaceous to Eocene magmatic-arc rocks, and trench generated ophiolites and blueschists produced by SW directed subduction. The oldest rocks in central Hispaniola are exposed in NW trending linear fault-bounded belts. Unusual high-Mg greenschists and amphibolites, quartz-feldspathic greenschists, together with N-type MORB basalts and keratophyric volcanics, are juxtaposed against a medial serpentinite belt. Central and eastern Puerto Rico consist of Lower to Upper Cretaceous volcanic rocks intruded by upper Cretaceous to Eocene plutons. Similar Cretaceous volcanics occur in SW Puerto Rico, but they are overthrust by Upper Jurassic cherts, spilites and amphibolites. Jamaica lies along the Nicaraguan Rise to the SW of the other islands and consists of Barremian to Maastrichtian volcanics and volcanogenic sediments intruded by upper Cretaceous calc-alkalic plutons. Blueschists and related rocks in eastern Jamaica, and geochemical zonation in the igneous rocks suggest that the subduction was to the NW. Change in tectonic movements from convergence to left lateral shear took place during the Late Eocene/Early Oligocene.

  10. Greater Green River Basin Production Improvement Project

    SciTech Connect

    DeJarnett, B.B.; Lim, F.H.; Calogero, D.

    1997-10-01

    The Greater Green River Basin (GGRB) of Wyoming has produced abundant oil and gas out of multiple reservoirs for over 60 years, and large quantities of gas remain untapped in tight gas sandstone reservoirs. Even though GGRB production has been established in formations from the Paleozoic to the Tertiary, recent activity has focused on several Cretaceous reservoirs. Two of these formations, the Ahnond and the Frontier Formations, have been classified as tight sands and are prolific producers in the GGRB. The formations typically naturally fractured and have been exploited using conventional well technology. In most cases, hydraulic fracture treatments must be performed when completing these wells to to increase gas production rates to economic levels. The objectives of the GGRB production improvement project were to apply the concept of horizontal and directional drilling to the Second Frontier Formation on the western flank of the Rock Springs Uplift and to compare production improvements by drilling, completing, and testing vertical, horizontal and directionally-drilled wellbores at a common site.

  11. Water soluble and insoluble components of urban PM2.5 and their cytotoxic effects on epithelial cells (A549) in vitro.

    PubMed

    Zou, Yajuan; Jin, Chengyu; Su, Yue; Li, Jiaru; Zhu, Bangshang

    2016-05-01

    When PM2.5 enters human bodies, the water soluble (WS-PM2.5) and insoluble components (WIS-PM2.5) of PM2.5 would interact with cells and cause adverse effects. However, the knowledge about the individual toxicity contribution of these two components is limited. In this study, the physiochemical properties of PM2.5 were well characterized. The toxic effects of WS-PM2.5 and WIS-PM2.5, which include the cell viability, cell membrane damage, reactive oxygen species (ROS) generation and morphological changes, were examined with human lung epithelial A549 cells in vitro. The results indicated that WS-PM2.5 could induce the early response of ROS generation, multiplied mitochondria and multi-lamellar bodies in A549 cells, which might cause cell damage through oxidative stress. Meanwhile, WIS-PM2.5 was predominantly associated with the cell membrane disruption, which might lead to the cell damage through cell-particle interactions. Moreover, the synergistic cytotoxic effects of WS-PM2.5 and WIS-PM2.5 were observed at longer exposure time. These findings demonstrate the different cytotoxicity mechanisms of WS-PM2.5 and WIS-PM2.5, which suggest that not only the size and dosage of PM2.5 but also the solubility of PM2.5 should be taken into consideration when evaluating the toxicity of PM2.5. PMID:27039898

  12. Chemical composition of size-resolved particulate matter at near-freeway and urban background sites in the greater Beirut area

    NASA Astrophysics Data System (ADS)

    Daher, Nancy; Saliba, Najat A.; Shihadeh, Alan L.; Jaafar, Malek; Baalbaki, Rima; Sioutas, Constantinos

    2013-12-01

    To characterize road-traffic emissions in the greater Beirut area, size-resolved PM10-2.5, PM2.5-0.25 and PM0.25 samples were concurrently collected at near-freeway and background sites. While particle mass levels were 1.3-2.6 times greater at the roadside than background location, PM10-2.5 and PM0.25 prevailed at both sites (36-43% of PM10). A chemical mass closure showed that PM10-2.5 was mostly composed of crustal material, contributing to 12-23% of its mass across sites. On the other hand, in PM2.5-0.25 and PM0.25, organic matter (46-56%) was dominant at the roadside location, while secondary ions (SI, 54-68%) were more abundant at the background site. In the vicinity of the freeway, organic carbon (OC) levels varied from 4 μg m-3 in PM10-2.5 to 10.1 μg m-3 in PM0.25, exceeding those at the background site by 4-7 times. In contrast, OC was largely water-soluble at the background location, with its water-soluble fraction displaying comparable PM2.5-0.25- and PM0.25-concentrations at both sites, corroborating its regional secondary origin. PM0.25-elemental carbon (EC), which dominated overall EC mass, was 7-fold greater at the near-freeway than background location, indicating a contribution from diesel or also smoking vehicles to road-traffic emissions. PM2.5-SI showed fairly uniform concentrations across sites, confirming their mainly regional source. Polycyclic aromatic hydrocarbons (PAHs) were undetected at the coastal background site, whereas their levels peaked at 11.5 ng m-3 in proximity to the freeway, with the majority confined to PM0.25. Compared to other roadways, organic compounds at the freeway location exhibited high hopanes plus steranes-to-total carbon ratios (0.16-1.1 ng μg-1), indicative of different engine configurations, fleet or also lubricating oil formulation. At both locations, PM0.25-bound n-alkanes (C19-C34) showed a predominance of high molecular weight homologues and no carbon number preference, suggesting their likely road dust

  13. 2.5D complex resistivity modeling and inversion using unstructured grids

    NASA Astrophysics Data System (ADS)

    Xu, Kaijun; Sun, Jie

    2016-04-01

    The characteristic of complex resistivity on rock and ore has been recognized by people for a long time. Generally we have used the Cole-Cole Model(CCM) to describe complex resistivity. It has been proved that the electrical anomaly of geologic body can be quantitative estimated by CCM parameters such as direct resistivity(ρ0), chargeability(m), time constant(τ) and frequency dependence(c). Thus it is very important to obtain the complex parameters of geologic body. It is difficult to approximate complex structures and terrain using traditional rectangular grid. In order to enhance the numerical accuracy and rationality of modeling and inversion, we use an adaptive finite-element algorithm for forward modeling of the frequency-domain 2.5D complex resistivity and implement the conjugate gradient algorithm in the inversion of 2.5D complex resistivity. An adaptive finite element method is applied for solving the 2.5D complex resistivity forward modeling of horizontal electric dipole source. First of all, the CCM is introduced into the Maxwell's equations to calculate the complex resistivity electromagnetic fields. Next, the pseudo delta function is used to distribute electric dipole source. Then the electromagnetic fields can be expressed in terms of the primary fields caused by layered structure and the secondary fields caused by inhomogeneities anomalous conductivity. At last, we calculated the electromagnetic fields response of complex geoelectric structures such as anticline, syncline, fault. The modeling results show that adaptive finite-element methods can automatically improve mesh generation and simulate complex geoelectric models using unstructured grids. The 2.5D complex resistivity invertion is implemented based the conjugate gradient algorithm.The conjugate gradient algorithm doesn't need to compute the sensitivity matrix but directly computes the sensitivity matrix or its transpose multiplying vector. In addition, the inversion target zones are

  14. Source proximity and residential outdoor concentrations of PM2.5, OC, EC, and PAHs

    PubMed Central

    Polidori, A.; Kwon, J.; Turpin, B.J.; Weisel, C.

    2015-01-01

    We examined the effect of proximity to specific mobile, area, and point sources on the residential outdoor concentrations of fine particulate matter PM (PM2.5) and several of its particle components. Integrated (48-h) PM2.5 samples were collected outside non-smoking residences in Elizabeth, NJ, between summer 1999 and spring 2001. Samples were analyzed for PM2.5 mass, organic and elemental carbon (OC and EC, respectively), trace elements, particle-phase polycyclic aromatic hydrocarbons (p-PAHs), and other important particle species. Information about the proximity of the study homes to potential mobile and area sources of OC, EC, p-PAHs, sulfur (S), and selenium (Se) (including urban interstate highways, local roadways, the Newark International Airport, the Elizabeth seaport, and a nearby refinery in Linden, NJ) were retrieved from a database that included detailed emissions, meteorological, and geographical data for the study area. The dependence of residential outdoor concentrations on source proximity and on various meteorological parameters was then examined for each species by multiple linear regression analysis. As expected, the predicted ambient air concentrations of all particle species (except S, Se) decreased with increasing distance from the sources. Although the enhancement in PM2.5 and OC levels outside the study homes closest to primary PM sources was modest (e.g., 1.6 and 2.5 times the background levels 37 m from interstate highways), the elevation of EC and p-PAH concentrations was substantial outside the closest study homes (i.e., about 20 times for p-PAHs 37 m from interstate highways and about 14 times for EC 192 m from the refinery in Linden, NJ). The predicted EC concentrations 192 and 500 m from the oil refinery were 22.8 and 3.0 µgC/m3, compared with an urban background of 1 µgC/m3. Thus, emissions from this source might dramatically affect EC exposure for residents living in its close proximity. PMID:19623217

  15. Source proximity and residential outdoor concentrations of PM(2.5), OC, EC, and PAHs.

    PubMed

    Polidori, A; Kwon, J; Turpin, B J; Weisel, C

    2010-07-01

    We examined the effect of proximity to specific mobile, area, and point sources on the residential outdoor concentrations of fine particulate matter PM (PM(2.5)) and several of its particle components. Integrated (48-h) PM(2.5) samples were collected outside non-smoking residences in Elizabeth, NJ, between summer 1999 and spring 2001. Samples were analyzed for PM(2.5) mass, organic and elemental carbon (OC and EC, respectively), trace elements, particle-phase polycyclic aromatic hydrocarbons (p-PAHs), and other important particle species. Information about the proximity of the study homes to potential mobile and area sources of OC, EC, p-PAHs, sulfur (S), and selenium (Se) (including urban interstate highways, local roadways, the Newark International Airport, the Elizabeth seaport, and a nearby refinery in Linden, NJ) were retrieved from a database that included detailed emissions, meteorological, and geographical data for the study area. The dependence of residential outdoor concentrations on source proximity and on various meteorological parameters was then examined for each species by multiple linear regression analysis. As expected, the predicted ambient air concentrations of all particle species (except S, Se) decreased with increasing distance from the sources. Although the enhancement in PM(2.5) and OC levels outside the study homes closest to primary PM sources was modest (e.g., 1.6 and 2.5 times the background levels 37 m from interstate highways), the elevation of EC and p-PAH concentrations was substantial outside the closest study homes (i.e., about 20 times for p-PAHs 37 m from interstate highways and about 14 times for EC 192 m from the refinery in Linden, NJ). The predicted EC concentrations 192 and 500 m from the oil refinery were 22.8 and 3.0 microgC/m(3), compared with an urban background of 1 microgC/m(3). Thus, emissions from this source might dramatically affect EC exposure for residents living in its close proximity. PMID:19623217

  16. Control of PM2.5 in Guangzhou during the 16th Asian Games period: implication for hazy weather prevention.

    PubMed

    Tao, Jun; Zhang, Leiming; Zhang, Zhisheng; Huang, Ruijin; Wu, Yunfei; Zhang, Renjian; Cao, Junji; Zhang, Yuanhang

    2015-03-01

    To evaluate the effectiveness of the integrated control measures for reducing PM2.5 (aerosol particles with an aerodynamic diameter of less than 2.5 μm) and hazy weather, day- and night-time PM2.5 samples were collected at an urban site in Guangzhou during the 16th Asian Games period in November 2010. PM2.5 samples were subject to chemical analysis for major water-soluble ions, organic carbon (OC), element carbon (EC), and biomass burning tracers-anhydrosugar levoglucosan (LG). In addition, aerosol scattering coefficient (bsp) at dry condition and aerosol absorption coefficient (bap) and visibility at ambient condition were measured. The seven major control measures were effective for reducing PM2.5 mass concentration and improving visibility during the Asian Games period. All monitored air pollutants except PM2.5 satisfied the National Ambient Air Quality Standards (NAAQS). However, daily PM2.5 concentrations still exceeded the NAAQS on 47% of the days and hazy weather also occurred on 80% of the days during this period. One factor causing the high frequency of hazy weather occurrence was the increased relative humidity during the Asian Games period. To avoid hazy weather occurrence, new PM2.5 standard was recommended based on visibility calculations using three available aerosol hygroscopic curves previously obtained for this city. The recommended PM2.5 standard was 63 μgm(-3) under dry condition and lower than 42 μg m(-3) under humid condition (RH ≥ 70%). These recommended value s were much stricter than the NAAQS value of 75 μg m(-3). To reach the new standard, more rigorous control measures for coal industries should be established in the Pearl River Delta (PRD) region. PMID:25437953

  17. 43 CFR 3712.2-5 - Proof of publication.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... or publication a sworn statement that the notice was published at the time and in accordance with the requirements under the regulations of this part, and shall file such sworn statement in the office where...

  18. 43 CFR 3712.2-5 - Proof of publication.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... or publication a sworn statement that the notice was published at the time and in accordance with the requirements under the regulations of this part, and shall file such sworn statement in the office where...

  19. An analysis on the concentration characteristics of PM2.5 in Seoul, Korea from 2005 to 2012

    NASA Astrophysics Data System (ADS)

    Lee, Miyeon

    2014-11-01

    PM2.5 is a big issue as it is considerably more harmful than other sizes of particulate matter. World Health Organization (WHO) recommends 25 μg m-3 as the daily average concentration, and 10 μg m-3 per day as an annual average. To keep up with global trends, it is first necessary to understand the current status and characteristics of PM2.5 concentrations in Korea. Using the PM2.5 data measured by Seoul Metropolitan City from November 2005 to March 2012, the author analyzed its statistical characteristics and correlations with other air pollutants. For the time period from 2005 to 2012, the annual average concentration of PM2.5 was 27 μg m-3, three times the WHO standard. Also, the daily average PM2.5 concentration of 215 days per year also exceeded the WHO standard. However, the number days exceeding the Korean daily average standard of 50 μg m-3 to be enacted in 2014 was only three. PM2.5 concentration had a high correlation (r = 0.84) with PM10, and also showed high correlations with gaseous pollutants, such as SO2, NO2, and CO, but not O3. This study suggests that the Korean government should strengthen their standard to match the criteria used by WHO.

  20. Environmentally Persistent Free Radicals and Their Lifetimes in PM2.5

    PubMed Central

    Gehling, William; Dellinger, Barry

    2015-01-01

    For the first time, an expansive study into the concentration and extended decay behavior of environmentally persistent free radicals in PM2.5 was performed. Results from this study revealed three types of radical decay—a fast decay, slow decay, and no decay—following one of four decay patterns: a relatively fast decay exhibiting a 1/e lifetime of 1–21 days accompanied by a slow decay with a 1/e lifetime of 21–5028 days (47% of samples); a single slow decay including a 1/e lifetime of 4–2083 days (24% of samples); no decay (18% of samples); and a relatively fast decay displaying an average 1/e lifetime of 0.25–21 days followed by no decay (11% of samples). Phenol correlated well with the initial radical concentration and fast decay rate. Other correlations for common atmospheric pollutants (ozone, NOx, SO2, etc.) as well as meteorological conditions suggested photochemical processes impact the initial radical concentration and fast decay rate. The radical signal in PM2.5 was remarkably similar to semiquinones in cigarette smoke. Accordingly, radicals inhaled from PM2.5 were related to the radicals inhaled from smoking cigarettes, expressed as the number of equivalent cigarettes smoked. This calculated to 0.4–0.9 cigarettes per day for nonextreme air quality in the United States. PMID:23844657

  1. Indoor, outdoor and regional profiles of PM2.5 sulfate, nitrateand carbon

    SciTech Connect

    Hering, S.V.; Lunden, M.M.; Kirchstetter, T.W.; Thatcher, T.L.; Revzan, K.L.; Sextro, R.G.; Brown, N.J.; Watson, J.; Chow, J.

    2002-01-31

    Fine particle concentrations were measured simultaneously at three locations: a regional monitoring site in Fresno, California, a backyard of an unoccupied residence in Clovis, California located 6 km northeast of the regional site; and indoors at the same residence. Measurements included 10-min determination of PM{sub 2.5} nitrate, sulfate and carbon using an automated collection and vaporization system, and black carbon measured by light attenuation through a filter deposit. Specific outdoor PM{sub 2.5} constituents were compared to assess the appropriateness of using regional data to model indoor concentrations from outdoor sources. The outdoor data show that, in general, the regional results provide a good representation of the concentrations seen at the building exterior. The indoor concentrations showed considerable attenuation as well as a broadening and time-lag for the concentration peaks. The concentration reduction was the largest for PM{sub 2.5} nitrate, which appears to undergo phase changes in addition to indoor deposition and penetration losses.

  2. Exposure to PM2.5 and PAHs from the Tong Liang, China epidemiological study.

    PubMed

    Chow, Judith C; Watson, John G; Chen, Lung-Wen Antony; Ho, Steven Sai Hang; Koracin, Darko; Zielinska, Barbara; Tang, Deliang; Perera, Frederica; Cao, Junji; Lee, S C

    2006-01-01

    Chemically speciated PM2.5 and particle-bound polycyclic aromatic hydrocarbon (PAH) measurements were made at three sites near urban Tong Liang, Chongqing, a Chinese inland city where coal combustion is used for electricity generation and residential purposes outside of the central city. Ambient sampling was based on 72-hr averages between 3/2/2002 and 2/26/2003. Elevated PM2.5 and PAH concentrations were observed at all three sites, with the highest concentrations found in winter and the lowest in summer. This reflects a coupling effect of source variability and meteorological conditions. The PM2.5 mass estimated from sulfate, nitrate, ammonium, organics, elemental carbon, crustal material, and salt corresponded with the annual average gravimetric mass within +/-10%. Carbonaceous aerosol was the dominant species, while positive correlations between organic carbon and trace elements (e.g., As, Se, Br, Pb, and Zn) were consistent with coal-burning and motor vehicle contributions. Ambient particle-bound PAHs of molecular weight 168-266 were enriched by 1.5 to 3.5 times during the coal-fired power plant operational period. However, further investigation is needed to determine the relative contribution from residential and utility coal combustion and vehicular activities. PMID:16779929

  3. Source attribution of PM2.5 pollution over North China using the adjoint method

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Liu, L.; Zhao, Y.; Gong, S.; Henze, D. K.

    2014-12-01

    Conventional methods for source attribution of air pollution are based on measurement statistics (such as Positive Matrix Factorization) or sensitivity simulations with a chemical transport model (CTM). These methods generally ignore the nonlinear chemistry associated with the pollution formation or require unaffordable computational time. Here we use the adjoint of GEOS-Chem CTM at 0.25x0.3125 degree resolution to examine the sources contributing to the PM2.5 pollution over North China in winter 2013. We improved the model sulfate simulation by implementing the aqueous-phase oxidation of S(IV) by nitrogen dioxide. The adjoint results provide detailed source information at the model underlying grid resolution including source types and sectors. We show that PM2.5 pollution over Beijing and Baoding (Hebei) in winter was largely contributed by the large-scale residential and industrial burnings, and ammonia (NH3) emissions from agriculture activities. Nearly half of pollution was transported from outside of the city domains, and accumulated over 2-3 days. We also show under the current emission conditions, the PM2.5 concentrations over North China are more sensitive to NH3 emissions than NOx and SO2 emissions.

  4. [Separation of PM2.5 from coal combustion with phase change].

    PubMed

    Yan, Jin-pei; Yang, Lin-jun; Zhang, Xia; Sun, Lu-juan; Zhang, Yu; Shen, Xiang-lin

    2008-12-01

    The influence of two methods of gas moisture conditioning on removal efficiency of PM2.5 from coal combustion with addition of atomized droplets and steam was investigated. The particles size distribution and number concentration were measured in real time by electrical low pressure impactor (ELPI). The results show that collection efficiency of PM2.5 from coal combustion can be highly improved with steam condensational enlargement. Particle stage collection efficiency increases with the particles, especially for those smaller than 0.3 microm. The separation efficiency can be improved by 60% with the size of particles increasing from 0.03 microm to 0.3 microm for 0.1 kg/m3 of steam addition. The removal efficiency is independent of the gas temperature at the inlet of conditioning chamber for steam addition. But it increases with the gas temperature obviously for atomized droplets addition, which can be improved by 30% with increasing gas temperature from 136 degrees C to 256 degrees C. High removal efficiency of PM2.5 from coal combustion can be obtained with atomized droplets evaporation in hot flue gas except for steam addition. PMID:19256364

  5. Sequential Measurement of Intermodal Variability in Public Transportation PM2.5 and CO Exposure Concentrations.

    PubMed

    Che, W W; Frey, H Christopher; Lau, Alexis K H

    2016-08-16

    A sequential measurement method is demonstrated for quantifying the variability in exposure concentration during public transportation. This method was applied in Hong Kong by measuring PM2.5 and CO concentrations along a route connecting 13 transportation-related microenvironments within 3-4 h. The study design takes into account ventilation, proximity to local sources, area-wide air quality, and meteorological conditions. Portable instruments were compacted into a backpack to facilitate measurement under crowded transportation conditions and to quantify personal exposure by sampling at nose level. The route included stops next to three roadside monitors to enable comparison of fixed site and exposure concentrations. PM2.5 exposure concentrations were correlated with the roadside monitors, despite differences in averaging time, detection method, and sampling location. Although highly correlated in temporal trend, PM2.5 concentrations varied significantly among microenvironments, with mean concentration ratios versus roadside monitor ranging from 0.5 for MTR train to 1.3 for bus terminal. Measured inter-run variability provides insight regarding the sample size needed to discriminate between microenvironments with increased statistical significance. The study results illustrate the utility of sequential measurement of microenvironments and policy-relevant insights for exposure mitigation and management. PMID:27182735

  6. Evaluation of a U.S. National Emissions Inventory of PM2.5 Species

    NASA Astrophysics Data System (ADS)

    Reff, A.; Bhave, P.; Zubrow, A.; Rao, V.

    2012-12-01

    This work explores the potential of speciating PM2.5 emissions to evaluate inventories against ambient pollutant measurements. Previously developed (Reff et al., Environ. Sci Technol., 2009, vol. 43, 5790-5796) source profiles of PM2.5 trace elements, carbon, and ions are applied to the U.S. EPA's 2005 National Emissions Inventory (NEI) to create a database of emissions disaggregated by species, source category, location, and time period (annual and monthly). These emissions are then "diluted" to produce projected ambient concentrations, which can be directly compared to measurements from monitoring networks. Dilution is performed by multiplying emissions against ratios of elemental carbon (EC) concentrations to EC emissions from a CMAQ modeling run that employed the same version of the NEI. After emissions dilution and spatial aggregation to the Core-Based Statistical Area (CBSA) level, various statistical and graphical comparisons of ambient measurements to emissions in each of the four dimensions above are then performed to diagnose gross errors in the 2005 PM2.5 NEI. Results are anticpated to be highly useful for developing future versions of the NEI, since they will allow developers to focus their efforts on the regions of the inventory that are most in need of improvement.

  7. Exposure to PM2.5 and PAHs from the Tong Liang, China epidemiological study

    SciTech Connect

    Chow, J.C.; Watson, J.G.; Chen, L.W.A.; Ho, S.S.H.; Koracin, D.; Zielinska, B.; Tang, D.L.; Perera, F.; Cao, J.J.; Lee, S.C.

    2006-07-01

    Chemically speciated PM2.5 and particle-bound polycyclic aromatic hydrocarbon (PAH) measurements were made at three sites near urban Tong Liang, Chongqing, a Chinese inland city where coal combustion is used for electricity generation and residential purposes outside of the central city. Ambient sampling was based on 72-hr averages between 3/2/2002 and 2/26/2003. Elevated PM2.5 and PAH concentrations were observed at all three sites, with the highest concentrations found in winter and the lowest in summer. This reflects a coupling effect of source variability and meteorological conditions. The PM2.5 mass estimated from sulfate, nitrate, ammonium, organics, elemental carbon, crustal material, and salt corresponded with the annual average gravimetric mass within 10%. Carbonaceous aerosol was the dominant species, while positive correlations between organic carbon and trace elements (e.g., As, Se, Br, Pb, and Zn) were consistent with coal-burning and motor vehicle contributions. Ambient particle-bound PAHs of molecular weight 168-266 were enriched by 1.5 to 3.5 times during the coal-fired power plant operational period. However, further investigation is needed to determine the relative contribution from residential and utility coal combustion and vehicular activities.

  8. Assessment of PM2.5 concentrations on Human Health: A case study of Delhi, India

    NASA Astrophysics Data System (ADS)

    Goyal, P.; Mishra, D.

    2015-12-01

    Connection of air quality with human health is well established in the literature. However the associated health risks due to fine particulate matter (PM2.5) concentration is not well known in India, while the assigned mean threshold values are 60 μg/m3 for 24-hour period and 40 μg/m3 for annual period. Both are considered safe concentration limits regarding human health effects. However, the daily and annually concentrations of PM2.5 were observed more than three times of NAAQS in the present study for a year. This study relates the incessant exposure to significant levels of PM2.5 to deleterious health effects, such as heart and lung diseases. The relation between environmental air quality and human health has been studied through different parameters e.g., hazard quotient (HQ), lifetime incremental cancer risk (LICR), and individual risk for different groups of ages in Delhi, the capital city of India. These analysis lead to additional insights into health disparities and may suggest that more rigorous strategies. This may be application to other urban areas across the nation. In this study, we propose to quantify such impacts through estimation of different health risk factors.

  9. Comparative neurotoxicity and pyrrole-forming potential of 2,5-hexanedione and perdeuterio-2,5-hexanedione in the rat

    SciTech Connect

    DeCaprio, A.P.; Briggs, R.G.; Jackowski, S.J.; Kim, J.C.

    1988-01-01

    2,5-Hexanedione (2,5-HD), the neurotoxic metabolite of n-hexane, reacts with protein amines to form alkylpyrrole adducts. Pyrrolylation of neurofilament protein may be the initiating molecular event in 2,5-HD neuropathy. The present study compares the neurotoxic and pyrrole-forming potentials of 2,5-HD with those of perdeuterio-2,5-HD ((D10)-2,5-HD) in the rat. Due to a requirement for C-H bond breaking in the reaction mechanism, the latter derivative was expected to exhibit a primary isotope effect, thus forming the pyrrole at a slower rate. In vitro studies confirmed that (D10)-2,5-HD pyrrolylated protein at only one-third of the initial rate seen with native 2,5-HD. Prolonged incubation resulted in similar pyrrole concentrations with both derivatives. Adult, male Wistar rats were administered daily (5 days/week) ip doses of either 3.5 mmol 2,5-HD or (D10)-2,5-HD/kg/day for 17 days or 2.5 mmol/kg/day for 38 days. At termination, animals administered 2,5-HD and (D10)-2,5-HD exhibited 27 and 8% body weight loss, respectively. Moderate to severe hindlimb paralysis was present in the 2,5-HD groups while only mild effects were seen in (D10)-2,5-HD-dosed rats. Neuropathological changes were prominent in spinal cord sections from 2,5-HD-treated animals, while no effects were present in rats given the deuterated derivative. Pyrrole adduct concentrations in serum and axonal cytoskeletal proteins from 2,5-HD-treated animals were two- to threefold higher than in rats given equimolar doses of (D10)-2,5-HD. Levels of covalent crosslinking of axonal cytoskeletal proteins (assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) appeared to correlate with pyrrole concentrations. Tissue concentrations of each diketone isomer were not significantly different, indicating similar uptake of native and deuterated 2,5-HD.

  10. Changing Water Environment in the Greater Jakarta Basins

    NASA Astrophysics Data System (ADS)

    Pawitan, H.; Delinom, R.; Lubis, R. F.

    2014-12-01

    Recent rapid economic development in the greater Jakarta areas has caused not only increased water resources demands but also affects the water environment due to population increase and land use changes, that further causes land degradation, and changes in hydrologic regimes and environmental qualities. In the present study, the water environmental capacities as indicated by the changing landscapes in the greater Jakarta basins were investigated to understand the role of land use management and its impact on water resources, ecosystem and environmental services. The Ciliwung river basin where rapid population increases and progresses of the land use/cover changes occurring was selected as a representative basin, and 41 water samplings were taken at different time of Jan. 08, Apr. 08, Jul. 08, and Oct. 08 during 2009 to understand the effect of rainfall variation on water quality, and clarify the characteristics of hydrological cycle. Landuse changes of the upper basins as can be seen for the upper basin indicated the expansion of settlements during 1990 to 2004 from 4.1% to 17.6% or in acreage increased almost five times, not only converting forested area, but mostly taking place from paddy fields that contributed about 50% of the additional land for new settlements. Urbanization expanding around the greater Jakarta basins, is closely related to the increased fluctuations of river discharges in recent years, with recurrence floods quickly after heavy rainfall events. Furthermore, the study results indicated that water quality of Ciliwung river, especially the loading concentrations of nitric acid closely reflects the population densities of the watershed. These results suggest that the land use/cover changes of the greater Jakarta basins affect largely the change of water environment of the areas and resulting a deteriorated factor for water resources, ecosystems and environmental services in both of quantity and quality

  11. A High-Resolution Two-Stage Satellite Model to Estimate PM2.5 Concentrations in China

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Ma, Z.; Hu, X.; Yang, K.

    2014-12-01

    With the rapid economic development and urbanization, severe and widespread PM2.5 pollution in China has attracted nationwide attention. Study of the health impact of PM2.5 exposure has been hindered, however, by the limited coverage of ground measurements from recently established regulatory monitoring networks. Estimating ground-level PM2.5 from satellite remote sensing is a promising new method to evaluate the spatial and temporal patterns of PM2.5 exposure. We developed a two-stage spatial statistical model to estimate daily mean PM2.5 concentrations at 10 km resolution in 2013 in China using MODIS Collection 6 AOD, assimilated meteorology, population density, and land use parameters. A custom inverse variance weighting approach was developed to combine MODIS Dark Target (DT) and Deep Blue (DB) AOD to optimize coverage. Compared with the AERONET AOD measurements, our combined AOD (R2=0.80, mean bias = 0.07) performs similarly to MODIS' combined AOD (R2=0.81, mean bias =0.07), but has 90% greater coverage. We used the first-stage linear mixed effect model to represent the temporal variability of PM2.5 and the second-stage generalized additive model to represent its spatial contrast. The overall model cross-validation R2 and relative prediction error are 0.80 and 30%, respectively. PM2.5 levels exhibit strong seasonal patterns, with the highest national mean concentrations in winter (75 µg/m3) and the lowest in summer (30 µg/m3). Elevated annual mean PM2.5 levels are predicted in North China Plain and Sichuan Basin, with the maximum annual PM2.5 concentrations higher than 130 µg/m3 and 110 µg/m3, respectively. Our results also indicates that over 94% of the Chinese population lives in areas that exceed the WHO Air Quality Interim Target-1 standard (35 μg/m3). The exceptions include Taiwan, Hainan, Yunnan, Tibet, and North Inner Mongolia.

  12. Polar organic tracers in PM2.5 aerosols from forests in eastern China

    NASA Astrophysics Data System (ADS)

    Wang, W.; Wu, M. H.; Li, L.; Zhang, T.; Li, H. J.; Wang, Y. J.; Liu, X. D.; Sheng, G. Y.; Claeys, M.; Fu, J. M.

    2008-06-01

    Photooxidation products of biogenic volatile organic compounds, mainly isoprene and monoterpenes, are significant sources of atmospheric particulate matter in forested regions. The objectives of this study were to examine time trends and diurnal variations of polar organic tracers for the photooxidation of isoprene and α-pinene to investigate whether they are linked with meteorological parameters or trace gases and to estimate their regional carbon contributions. PM2.5 (particulate matter with an aerodynamic diameter <2.5 μm) aerosol samples were collected from forests in eastern China and compared with data from forested sites in Europe and America. Aerosol sampling was conducted at four sites located along a gradient of ecological succession in four different regions of China, i.e. Changbai Mountain Nature Reserve (boreal-temperate), Chongming National Forest Park (temperate), Dinghu Mountain Nature Reserve (subtropical) and Jianfengling Nature Reserve (tropical) during summer periods when the meteorological conditions are believed to be favorable for photochemical processes. Fifty PM2.5 samples were collected; seventeen organic compounds, organic carbon (OC), elemental carbon and trace gases were measured. Results indicate that the concentration trends of the secondary organic compounds reflected those of the trace gases and meteorological parameters. The 24-h average concentrations of isoprene oxidation products, α-pinene oxidation products, sugars and sugar alcohols vary systematically along gradients of ecological succession, except malic acid which may have both biogenic and anthropogenic sources. The maximum carbon contribution of isoprene and α-pinene oxidation products to the OC was 2.4% (293 ng/m3, Changbai day-time) and 0.3% (41.3 ng/m3, Changbai night-time), respectively.

  13. Environmental Particulate (PM2.5) Augments Stiffness-Induced Alveolar Epithelial Cell Mechanoactivation of Transforming Growth Factor Beta

    PubMed Central

    Dysart, Marilyn M.; Galvis, Boris R.; Russell, Armistead G.; Barker, Thomas H.

    2014-01-01

    Dysfunctional pulmonary homeostasis and repair, including diseases such as pulmonary fibrosis (PF), chronic obstructive pulmonary disease (COPD), and tumorigenesis have been increasing over the past decade, a fact that heavily implicates environmental influences. Several investigations have suggested that in response to increased transforming growth factor - beta (TGFβ) signaling, the alveolar type II (ATII) epithelial cell undergoes phenotypic changes that may contribute to the complex pathobiology of PF. We have previously demonstrated that increased tissue stiffness associated with PF is a potent extracellular matrix (ECM) signal for epithelial cell activation of TGFβ. The work reported here explores the relationship between tissue stiffness and exposure to environmental stimuli in the activation of TGFβ. We hypothesized that exposure of ATII cells to fine particulate matter (PM2.5) will result in enhanced cell contractility, TGFβ activation, and subsequent changes to ATII cell phenotype. ATII cells were cultured on increasingly stiff substrates with or without addition of PM2.5. Exposure to PM2.5 resulted in increased activation of TGFβ, increased cell contractility, and elongation of ATII cells. Most notably, on 8 kPa substrates, a stiffness greater than normal but less than established fibrotic lung, addition of PM2.5 resulted in increased cortical cell stiffness, enhanced actin staining and cell elongation; a result not seen in the absence of PM2.5. Our work suggests that PM2.5 exposure additionally enhances the existing interaction between ECM stiffness and TGFβ that has been previously reported. Furthermore, we show that this additional enhancement is likely a consequence of intracellular reactive oxygen species (ROS) leading to increased TGFβ signaling events. These results highlight the importance of both the micromechanical and biochemical environment in lung disease initiation and suggest that individuals in early stages of lung remodeling

  14. Third-order nonlinear optical property of a polyphenylene oligomer: poly(2,5-dialkozyphenylene)

    NASA Astrophysics Data System (ADS)

    Wu, Jianyao; Yan, Jun; Sun, Diechi; Li, Fuming; Zhou, Luwei; Sun, Meng

    1997-02-01

    The third-order nonlinear optical (NLO) property of a soluble, π-backbone conjugated polymer poly(2,5-dialkozyphenylene) (for abbreviation called dialkozy-PP) is studied at the picosecond time region. The near resonance third-order hyperpolarizability γxxxx at 532 nm is 8.2×10 -30 esu, and the corresponding macroscopic third-order susceptibility χ(3)(- ω, ω, ω, - ω) and nonlinear refractive index n2 are estimated to be 6.3×10 -10 esu and 1.4×10 -8 esu, respectively. The half-width of the laser pulse is 35 ps.

  15. Rock Art of the Greater Southwest

    NASA Astrophysics Data System (ADS)

    Krupp, Edwin C.

    Archaeoastronomical studies in the American Southwest began in 1955 with recognition of what seemed to be pictorial eyewitness records of the Crab supernova of 1054 AD In time, reports of seasonally significant light-and-shadow effects on rock art and associations of rock art with astronomical alignments also emerged. Most astronomical rock art studies remained problematic, however, because criteria for proof of ancient intent were elusive. Disciplined methods for assessing cultural function were difficult to develop, but review of ethnographically documented astronomical traditions of California Indians and of Indians in the American Southwest subsequently increased confidence in the value of some astronomical rock art initiatives.

  16. Does Unemployment Lead to Greater Alcohol Consumption?

    PubMed Central

    Popovici, Ioana; French, Michael T.

    2013-01-01

    Using panel data from Waves 1 and 2 of the NESARC, we estimate gender-specific effects of changes in employment status on overall alcohol consumption, binge drinking episodes, and a diagnosis of alcohol abuse and/or dependence. We employ various fixed-effects models to address potential bias from unobserved and time-invariant individual heterogeneity. All results show a positive and significant effect of unemployment on drinking behaviors and the findings are robust to numerous sensitivity tests. Perhaps macroeconomic policy decisions intended to stimulate the economy during economic downturns should also consider the avoided personal costs and externalities associated with alcohol misuse. PMID:23543880

  17. Promoting greater Federal energy productivity [Final report

    SciTech Connect

    Hopkins, Mark; Dudich, Luther

    2003-03-05

    This document is a close-out report describing the work done under this DOE grant to improve Federal Energy Productivity. Over the four years covered in this document, the Alliance To Save Energy conducted liaison with the private sector through our Federal Energy Productivity Task Force. In this time, the Alliance held several successful workshops on the uses of metering in Federal facilities and other meetings. We also conducted significant research on energy efficiency, financing, facilitated studies of potential energy savings in energy intensive agencies, and undertook other tasks outlined in this report.

  18. Distribution of Permo-Carboniferous clastics of Greater Arabian basin

    SciTech Connect

    Al-Laboun, A.A.

    1987-05-01

    Strikingly correlative sequences of sediments composed of sandstones, siltstones, shales, and thin argillaceous carbonate beds are present, practically everywhere, underlying the Late Permian carbonates in the Greater Arabian basin. The Greater Arabian basin as defined here occupies the broad Arabian Shelf that borders the Arabian shield. This basin is composed of several smaller basins. These clastics are exposed as thin bands and scattered small exposures in several localities around the margins of the basin. The Permo-Carboniferous clastics are represented by the Unayzah Formation of Arabia, the Doubayat Group of Syria, the Hazro Formation of southeast Turkey, the Ga'arah Formation of Iraq, the Faraghan Formation of southwest Iran, and the Haushi Group of Oman. A Late Carboniferous-Early Permian age is assigned to these clastics because they contain fossil plants and palynomorphs. These sediments represent time-transgressive fluctuating sea deposits following a phase of regional emergence, erosion, and structural disturbance which preceded the Permian transgression. The basal contact of these clastics is marked by a well-pronounced angular unconformity with various older units, ranging in age from early Carboniferous to late Precambrian. This regional unconformity is probably related to the Hercynian movements. The upper contact is conformable with the Permian carbonates. The porous sandstones of the Permo-Carboniferous sediments are important hydrocarbon exploration targets. These reservoir rocks sometimes overlie mature source rocks and are capped by shales, marls, and tight carbonates. Significant quantities of hydrocarbons are contained in these reservoirs in different parts of the Greater Arabian basin.

  19. Integrating parasitology and marine ecology: Seven challenges towards greater synergy

    NASA Astrophysics Data System (ADS)

    Poulin, Robert; Blasco-Costa, Isabel; Randhawa, Haseeb S.

    2016-07-01

    Despite their very different historical origins as scientific disciplines, parasitology and marine ecology have already combined successfully to make important contributions to our understanding of the functioning of natural ecosystems. For example, robust assessments of the contribution of parasites to ecosystem biomass and energetics, and of their impact on community-wide biodiversity and food web structure, have all been made for the first time in marine systems. Nevertheless, for the marriage between parasitology and marine ecology to remain fruitful, several challenges must first be overcome. We discuss seven such challenges on the road to a greater synergy between these disciplines: (1) Raising awareness of parasitism as an ecological force by increasing the proportion of articles about parasites and diseases in marine ecology journals; (2) Making greater use of theory and conceptual frameworks from marine ecology to guide parasitological research; (3) Speeding up or at least maintaining the current rate at which marine parasites are found and described; (4) Elucidating a greater proportion of life cycles in all major groups of marine parasites; (5) Increasing the number of host-parasite model systems on which our knowledge is based; (6) Extending parasitological research offshore and into ocean depths; and (7) Developing, as needed, new epidemiological theory and transmission models for the marine environment. None of these challenges is insurmountable, and addressing just a few of them should guarantee that parasitology and marine ecology will continue to join forces and make further substantial contributions.

  20. Concentrations and emission factors for PM2.5 and PM10 from road traffic in Sweden

    NASA Astrophysics Data System (ADS)

    Ferm, Martin; Sjöberg, Karin

    2015-10-01

    PM10 concentrations exceed the guidelines in some Swedish cities and the limit values will likely be further reduced in the future. In order to gain more knowledge of emission factors for road traffic and concentrations of PM10 and PM2.5, existing monitoring stations in two cities, Gothenburg and Umeå, with international E-road thoroughfares, were complemented with some PM2.5 measurements. Emission factors for PM10 and PM2.5 were estimated using NOX as a tracer. Monitoring data from kerbside and urban background sites in Gothenburg during 2006-2010 and in Umeå during 2006-2012 were used. NOX emissions were estimated from the traffic flow and emission factors calculated from the HBEFA3.1 model. PM2.5 constitutes the finer part of PM10. Emissions of the coarser part of PM10 (PM10-PM2.5) are suppressed when roads are wet and show a maximum during spring when the roads dry up and studded tyres are still used. Less than 1% of the road wear caused by studded tyres give rise to airborne PM2.5-10 particles. The NOX emission factors decrease with time in the used model, due to the renewal of the vehicle fleet. However, the NOX concentrations resulting from the roads show no clear trend. The air dispersion is an important factor controlling the PM concentration near the road. The dispersion has a minimum in winter and during midnight. The average street level concentrations of PM10 and PM2.5 in Gothenburg were 21 ± 20 and 8 ± 6 μg m-3 respectively, which is 36% and 22% higher than the urban background concentrations. Despite the four times lower traffic flow in Umeå compared to Gothenburg, the average particle concentrations were very similar; 21 ± 31 and 7 ± 5 μg m-3 for PM10 and PM2.5 respectively. These concentrations were, however, 108% and 55% higher than the urban background concentrations in Umeå. The emission factors for PM10 decreased with time, and the average factor was 0.06 g km-1 vehichle-1. The emission factors for PM2.5 are very uncertain due to the

  1. Chemical characteristics of PM2.5 during haze episodes in Beijing

    NASA Astrophysics Data System (ADS)

    Shen, Rongrong; Schaefer, Klaus; Suppan, Peter; Wang, Yuesi; Schnelle-Kreis, Jürgen; Shao, Longyi; Emeis, Stefan

    2014-05-01

    Haze episodes have become much more frequent in Beijing and have received more attention during the past decade because of its influences on visibility and human health. Due to the chemical characteristics and sources of haze, which are different from the normal urban aerosols, studies of haze pollution become more important for the control of air pollution in Beijing. This study aims to investigate the chemical characteristics of PM2.5 during haze episodes in Beijing in 2013 spring and the possible sources of chemical compounds during haze episodes. Two sequential High-Volume Samplers (Digitel DHA-80, Hegnau, Switzerland) were used to collect PM2.5 samples in Beijing automatically from 10 April to 8 June 2013. The inorganic elements, inorganic water-soluble ions, EC and OC of PM2.5 were analyzed by ICP-MS, IC and thermal/optical carbon analyzers respectively. Three haze episodes were found: 18 to 25 April, 3 to 9 May and 1 to 8 June. The average PM2.5 mass concentration during haze days was 140 µg m-3 while 45 µg m-3 during clear days. SO42-, NO3-, NH4+, Cl-, K+, Cu, Ni, Zn, As, Cd, Tl, Pb, EC and OC, mass concentrations increased during haze days, compared with concentrations during clear days. The main increase is that secondary inorganic pollutant mass concentrations (NO3-, SO42- and NH4+) were 6 times higher and mass percentages were 2 times higher. This indicates that the major chemical species of PM2.5 during haze episodes are originated from anthropogenic sources. NO3-, SO42- and NH4+ are basically formed by a gas-to-particle formation processes on the basis of chemical reactions of precursor gases. Mass ratio of NO3-/SO42- is widely used as an indicator to determine the importance of mobile sources and stationary sources of sulphur and nitrogen. The mass ratio of NO3-/SO42- during haze days (0.82) was higher than during clear days (0.68) suggesting that vehicle emission is an important reason for haze in Beijing. OC/EC mass ratio higher than 2 indicates

  2. Toward refined estimates of ambient PM2.5 exposure: Evaluation of a physical outdoor-to-indoor transport model

    NASA Astrophysics Data System (ADS)

    Hodas, Natasha; Meng, Qingyu; Lunden, Melissa M.; Turpin, Barbara J.

    2014-02-01

    Because people spend the majority of their time indoors, the variable efficiency with which ambient PM2.5 penetrates and persists indoors is a source of error in epidemiologic studies that use PM2.5 concentrations measured at central-site monitors as surrogates for ambient PM2.5 exposure. To reduce this error, practical methods to model indoor concentrations of ambient PM2.5 are needed. Toward this goal, we evaluated and refined an outdoor-to-indoor transport model using measured indoor and outdoor PM2.5 species concentrations and air exchange rates from the Relationships of Indoor, Outdoor, and Personal Air Study. Herein, we present model evaluation results, discuss what data are most critical to prediction of residential exposures at the individual-subject and populations levels, and make recommendations for the application of the model in epidemiologic studies. This paper demonstrates that not accounting for certain human activities (air conditioning and heating use, opening windows) leads to bias in predicted residential PM2.5 exposures at the individual-subject level, but not the population level. The analyses presented also provide quantitative evidence that shifts in the gas-particle partitioning of ambient organics with outdoor-to-indoor transport contribute significantly to variability in indoor ambient organic carbon concentrations and suggest that methods to account for these shifts will further improve the accuracy of outdoor-to-indoor transport models.

  3. Exceedances of air quality standard level of PM2.5 in Japan caused by Siberian wildfires

    NASA Astrophysics Data System (ADS)

    Ikeda, Kohei; Tanimoto, Hiroshi

    2015-10-01

    We revisited long-term observations of PM2.5 at ground-based stations in Japan during 2001-2012 to examine possible impacts of Siberian wildfires on regional air quality. Exceedances of Japan’s air quality standard for daily mean concentration (35 μg m-3) were observed several times at Rishiri Island in northern Japan in the spring of 2003 and 2008 when intense wildfires occurred in Siberia. Satellite observations showed that aerosols and CO originating from biomass burning were transported from Siberia toward Japan. The regional chemical transport model also demonstrated that the PM2.5 enhancements during high PM2.5 days (>35 μg m-3) were attributed to Siberian wildfires, suggesting that the contribution from Siberian biomass burning had a critical impact on exceedances of air quality standard level. The monthly (May) and annual mean PM2.5 concentrations in 2003 were about twice and 20% higher, respectively, than those of the long-term average at Rishiri Island, where the influence of Siberian wildfires was the largest in Japan. Except for 2003 and 2008, a high PM2.5 day due to Siberian wildfires was not identified. Although Siberian biomass burning does not affect the air quality standard of PM2.5 for the years without strong fires, it causes exceedance of the air quality standard level when intense fires occur.

  4. Intercomparison between satellite-derived aerosol optical thickness and PM2.5 mass: Implications for air quality studies

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Christopher, Sundar A.

    2003-11-01

    We explore the relationship between column aerosol optical thickness (AOT) derived from the Moderate Resolution Imaging SpectroRadiometer (MODIS) on the Terra/Aqua satellites and hourly fine particulate mass (PM2.5) measured at the surface at seven locations in Jefferson county, Alabama for 2002. Results indicate that there is a good correlation between the satellite-derived AOT and PM2.5 (linear correlation coefficient, R = 0.7) indicating that most of the aerosols are in the well-mixed lower boundary layer during the satellite overpass times. There is excellent agreement between the monthly mean PM2.5 and MODIS AOT (R > 0.9), with maximum values during the summer months due to enhanced photolysis. The PM2.5 has a distinct diurnal signature with maxima in the early morning (6:00 ~ 8:00AM) due to increased traffic flow and restricted mixing depths during these hours. Using simple empirical linear relationships derived between the MODIS AOT and 24hr mean PM2.5 we show that the MODIS AOT can be used quantitatively to estimate air quality categories as defined by the U.S. Environmental Protection Agency (EPA) with an accuracy of more than 90% in cloud-free conditions. We discuss the factors that affect the correlation between satellite-derived AOT and PM2.5 mass, and emphasize that more research is needed before applying these methods and results over other areas.

  5. Effects of water soluble PM2.5 extracts exposure on human lung epithelial cells (A549): A proteomic study.

    PubMed

    Huang, Qingyu; Zhang, Jie; Peng, Siyuan; Tian, Meiping; Chen, Jinsheng; Shen, Heqing

    2014-06-01

    Exposure to airborne particulate matter (PM)2.5, a PM with aerodynamic diameter of less than 2.5 µm, is known to be associated with a variety of adverse health effects. However, the molecular mechanisms involved in fine PM toxicity are still not well characterized. The present study aims to provide new insights into the cytotoxicity of PM2.5 on human lung epithelial cells (A549) at the proteomic level. Two-dimensional difference gel electrophoresis revealed a total of 27 protein spots, whose abundance were significantly altered in A549 cells exposed to water-soluble PM2.5 extracts (WSPE). Among these, 12 spots were upregulated while 15 were downregulated. Twenty-two proteins were further identified by matrix-assisted laser desorption/ionization time-of-flight tandem mass/mass spectrometry and database search. The results revealed that oxidative stress, metabolic disturbance, dysregulation of signal transduction, aberrant protein synthesis and degradation, as well as cytoskeleton disorganization are major factors contributing to WSPE-mediated toxicity in human lung cells. It is further proposed that induction of apoptosis through p53, c-Myc and p21 pathways may be one of the key toxicological events occurred in A549 cells under WSPE stress. The data obtained here will aid our understanding of the toxic mechanisms related to PM2.5, and develop useful biomarkers indicative of inhalable PM2.5 exposure. PMID:23943255

  6. Dust Monitoring on the Hanford Site: An Investigation into the Relationship Between TSP, PM-10, and PM-2.5

    SciTech Connect

    Schwartz, T.; Fitz, B.G.

    2004-01-01

    High levels of particulate matter (PM) are linked to some health problems and environmental issues. Air quality standards have been developed in hopes to reduce particulate matter problems. The most common fractions of particulate matter measured include PM2.5, PM10, and total suspended particles (TSP). The focus of this study was to evaluate relationships between PM2.5, PM10, and TSP concentrations specific to the Hanford Site, near Richland, Washington. Measurements of PM2.5 and PM10 concentrations continued while additional measurements of TSP were made over several summer months. Four sampling locations on the Hanford Site were used to compare spatial differences in the data. Comparison of the data revealed a strong linear correlation between PM10 and TSP for the time period evaluated. The correlation between PM2.5 and TSP was not as strong, and indicated that local sources rarely were above background measurements. This was supported by the correlation of ground level PM2.5 with PM2.5 concentrations measured on a near by mountain.

  7. Comparison of Four Ground-Level PM2.5 Estimation Models Using PARASOL Aerosol Optical Depth Data from China.

    PubMed

    Guo, Hong; Cheng, Tianhai; Gu, Xingfa; Chen, Hao; Wang, Ying; Zheng, Fengjie; Xiang, Kunshen

    2016-02-01

    Satellite remote sensing is of considerable importance for estimating ground-level PM2.5 concentrations to support environmental agencies monitoring air quality. However, most current studies have focused mainly on the application of MODIS aerosol optical depth (AOD) to predict PM2.5 concentrations, while PARASOL AOD, which is sensitive to fine-mode aerosols over land surfaces, has received little attention. In this study, we compared a linear regression model, a quadratic regression model, a power regression model and a logarithmic regression model, which were developed using PARASOL level 2 AOD collected in China from 18 January 2013 to 10 October 2013. We obtained R (correlation coefficient) values of 0.64, 0.63, 0.62, and 0.57 for the four models when they were cross validated with the observed values. Furthermore, after all the data were classified into six levels according to the Air Quality Index (AQI), a low level of statistical significance between the four empirical models was found when the ground-level PM2.5 concentrations were greater than 75 μg/m³. The maximum R value was 0.44 (for the logarithmic regression model and the power model), and the minimum R value was 0.28 (for the logarithmic regression model and the power model) when the PM2.5 concentrations were less than 75 μg/m³. We also discussed uncertainty sources and possible improvements. PMID:26840329

  8. Using high-resolution satellite aerosol optical depth to estimate daily PM2.5 geographical distribution in Mexico City

    PubMed Central

    Just, Allan C.; Wright, Robert O.; Schwartz, Joel; Coull, Brent A.; Baccarelli, Andrea A.; Tellez-Rojo, Martha María; Moody, Emily; Wang, Yujie; Lyapustin, Alexei; Kloog, Itai

    2015-01-01

    Recent advances in estimating fine particle (PM2.5) ambient concentrations use daily satellite measurements of aerosol optical depth (AOD) for spatially and temporally resolved exposure estimates. Mexico City is a dense megacity that differs from other previously modeled regions in several ways: it has bright land surfaces, a distinctive climatological cycle, and an elevated semi-enclosed air basin with a unique planetary boundary layer dynamic. We extend our previous satellite methodology to the Mexico City area, a region with higher PM2.5 than most US and European urban areas. Using a novel 1 km resolution AOD product from the MODIS instrument, we constructed daily predictions across the greater Mexico City area for 2004–2014. We calibrated the association of AOD to PM2.5 daily using municipal ground monitors, land use, and meteorological features. Predictions used spatial and temporal smoothing to estimate AOD when satellite data were missing. Our model performed well, resulting in an out-of-sample cross validation R2 of 0.724. Cross-validated root mean squared prediction error (RMSPE) of the model was 5.55 μg/m3. This novel model reconstructs long- and short-term spatially resolved exposure to PM2.5 for epidemiological studies in Mexico City. PMID:26061488

  9. Comparison of Four Ground-Level PM2.5 Estimation Models Using PARASOL Aerosol Optical Depth Data from China

    PubMed Central

    Guo, Hong; Cheng, Tianhai; Gu, Xingfa; Chen, Hao; Wang, Ying; Zheng, Fengjie; Xiang, Kunshen

    2016-01-01

    Satellite remote sensing is of considerable importance for estimating ground-level PM2.5 concentrations to support environmental agencies monitoring air quality. However, most current studies have focused mainly on the application of MODIS aerosol optical depth (AOD) to predict PM2.5 concentrations, while PARASOL AOD, which is sensitive to fine-mode aerosols over land surfaces, has received little attention. In this study, we compared a linear regression model, a quadratic regression model, a power regression model and a logarithmic regression model, which were developed using PARASOL level 2 AOD collected in China from 18 January 2013 to 10 October 2013. We obtained R (correlation coefficient) values of 0.64, 0.63, 0.62, and 0.57 for the four models when they were cross validated with the observed values. Furthermore, after all the data were classified into six levels according to the Air Quality Index (AQI), a low level of statistical significance between the four empirical models was found when the ground-level PM2.5 concentrations were greater than 75 μg/m3. The maximum R value was 0.44 (for the logarithmic regression model and the power model), and the minimum R value was 0.28 (for the logarithmic regression model and the power model) when the PM2.5 concentrations were less than 75 μg/m3. We also discussed uncertainty sources and possible improvements. PMID:26840329

  10. Using High-Resolution Satellite Aerosol Optical Depth To Estimate Daily PM2.5 Geographical Distribution in Mexico City.

    PubMed

    Just, Allan C; Wright, Robert O; Schwartz, Joel; Coull, Brent A; Baccarelli, Andrea A; Tellez-Rojo, Martha María; Moody, Emily; Wang, Yujie; Lyapustin, Alexei; Kloog, Itai

    2015-07-21

    Recent advances in estimating fine particle (PM2.5) ambient concentrations use daily satellite measurements of aerosol optical depth (AOD) for spatially and temporally resolved exposure estimates. Mexico City is a dense megacity that differs from other previously modeled regions in several ways: it has bright land surfaces, a distinctive climatological cycle, and an elevated semi-enclosed air basin with a unique planetary boundary layer dynamic. We extend our previous satellite methodology to the Mexico City area, a region with higher PM2.5 than most U.S. and European urban areas. Using a novel 1 km resolution AOD product from the MODIS instrument, we constructed daily predictions across the greater Mexico City area for 2004-2014. We calibrated the association of AOD to PM2.5 daily using municipal ground monitors, land use, and meteorological features. Predictions used spatial and temporal smoothing to estimate AOD when satellite data were missing. Our model performed well, resulting in an out-of-sample cross-validation R(2) of 0.724. Cross-validated root-mean-squared prediction error (RMSPE) of the model was 5.55 μg/m(3). This novel model reconstructs long- and short-term spatially resolved exposure to PM2.5 for epidemiological studies in Mexico City. PMID:26061488

  11. 40 CFR Table C-4 to Subpart C of... - Test Specifications for PM10, PM2.5 and PM10-2.5 Candidate Equivalent Methods

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Test Specifications for PM10, PM2.5 and PM10-2.5 Candidate Equivalent Methods C Table C-4 to Subpart C of Part 53 Protection of Environment... Pt. 53, Subpt. C, Table C-4 Table C-4 to Subpart C of Part 53—Test Specifications for PM10, PM2.5...

  12. 40 CFR Table C-4 to Subpart C of... - Test Specifications for PM10, PM2.5 and PM10-2.5 Candidate Equivalent Methods

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Test Specifications for PM10, PM2.5 and PM10-2.5 Candidate Equivalent Methods C Table C-4 to Subpart C of Part 53 Protection of Environment... Pt. 53, Subpt. C, Table C-4 Table C-4 to Subpart C of Part 53—Test Specifications for PM10, PM2.5...

  13. [Estimation of PM2.5 over eastern China from MODIS aerosol optical depth using the back propagation neural network].

    PubMed

    Guo, Jian-Ping; Wu, Ye-Rong; Zhang, Xiao-Ye; Li, Xiao-Wen

    2013-03-01

    With the fast economic development in China in recent years, air pollutions are becoming increasingly serious. It is, therefore, imperative to develop new technology to solve this issue. Due to the wide spatial coverage of satellite remote sensing, along with the relatively lower cost compared to ground-based in situ aerosol measurements, satellite retrieved aerosol optical depth (AOD) is widely recognized as a good surrogate of surface PM2.5 concentrations. In this study, two years (2007-2008) of AOD data from moderate resolution imaging spectroradiometer (MODIS) onboard Terra at five observational sites of China (Benxi, Zhengzhou, Lushan, Nanning, Guilin), combined with five meteorological factors such as wind speed, wind direction, temperature humidity and planetary boundary height, were used as important input to establish the Back Propagation (BP) neural networks model, which was applied to estimate PM2.5. Afterwards, the model estimated PM2.5 was validated by in situ PM2.5 measurements from the five sites. Specially, scatter analysis showed that the linear correlation coefficient (R) between ground PM2.5 observation and model estimated PM2.5 at Lushan was the highest (R = 0.6), whereas the R values at the four other sites were lower, ranging from 0.43 to 0.49. Time series validations were performed as well, indicating that the R value significantly varied from day to day. However, the R value could be significantly improved by fitting the five-day moving average ground observation values against the model estimated PM2.5 data. Also, the R value at Lushan was the highest (R = 0.83), suggesting that MODIS AOD can be used to monitor PM2.5 by the BP networks model developed in this study. PMID:23745382

  14. Exposure to PM2.5 and Blood Lead Level in Two Populations in Ulaanbaatar, Mongolia

    PubMed Central

    Enkhbat, Undarmaa; Rule, Ana M.; Resnick, Carol; Ochir, Chimedsuren; Olkhanud, Purevdorj; Williams, D’Ann L.

    2016-01-01

    Approximately 60% of the households in Ulaanbaatar live in gers (a traditional Mongolian dwelling) in districts outside the legal limits of the city, without access to basic infrastructure, such as water, sewage systems, central heating, and paved roads, in contrast to apartment residents. This stark difference in living conditions creates different public health challenges for Ulaanbaatar residents. Through this research study we aim to test our hypothesis that women living in gers burning coal in traditional stoves for cooking and heating during the winter are exposed to higher concentrations of airborne PM2.5 than women living in apartments in Ulaanbaatar, Mongolia, and this exposure may include exposures to lead in coal with effects on blood lead levels. This cross-sectional study recruited a total of 50 women, 40–60 years of age, from these two settings. Air sampling was carried out during peak cooking and heating times, 5:00 p.m.–11:00 p.m., using a direct-reading instrument (TSI SidePak™) and integrated polytetrafluoroethylene (PTFE) filters using the SKC Personal Environmental Monitor. Blood lead level (BLL) was measured using a LeadCare II rapid field test method. In our study population, measured PM2.5 geometric mean (GM) concentrations using the SidePak™ in the apartment group was 31.5 (95% CI:17–99) μg/m3, and 100 (95% CI: 67–187) μg/m3 in ger households (p < 0.001). The GM integrated gravimetric PM2.5 concentrations in the apartment group were 52.8 (95% CI: 39–297) μg/m3 and 127.8 (95% CI: 86–190) μg/m3 in ger households (p = 0.004). The correlation coefficient for the SidePak™ PM2.5 concentrations and filter based PM2.5 concentrations was r = 0.72 (p < 0.001). Blood Lead Levels were not statistically significant different between apartment residents and ger residents (p = 0.15). The BLL is statistically significant different (p = 0.01) when stratified by length of exposures outside of the home. This statistically significant

  15. Spectral investigations of 2,5-difluoroaniline by using mass, electronic absorption, NMR, and vibrational spectra

    NASA Astrophysics Data System (ADS)

    Kose, Etem; Karabacak, Mehmet; Bardak, Fehmi; Atac, Ahmet

    2016-11-01

    One of the most significant aromatic amines is aniline, a primary aromatic amine replacing one hydrogen atom of a benzene molecule with an amino group (NH2). This study reports experimental and theoretical investigation of 2,5-difluoroaniline molecule (2,5-DFA) by using mass, ultraviolet-visible (UV-vis), 1H and 13C nuclear magnetic resonance (NMR), Fourier transform infrared and Raman (FT-IR and FT-Raman) spectra, and supported with theoretical calculations. Mass spectrum (MS) of 2,5-DFA is presented with their stabilities. The UV-vis spectra of the molecule are recorded in the range of 190-400 nm in water and ethanol solvents. The 1H and 13C NMR chemical shifts are recorded in CDCl3 solution. The vibrational spectra are recorded in the region 4000-400 cm-1 (FT-IR) and 4000-10 cm-1 (FT-Raman), respectively. Theoretical studies are underpinned the experimental results as described below; 2,5-DFA molecule is optimized by using B3LYP/6-311++G(d,p) basis set. The mass spectrum is evaluated and possible fragmentations are proposed based on the stable structure. The electronic properties, such as excitation energies, oscillator strengths, wavelengths, frontier molecular orbitals (FMO), HOMO and LUMO energies, are determined by time-dependent density functional theory (TD-DFT). The electrostatic potential surface (ESPs), density of state (DOS) diagrams are also prepared and evaluated. In addition to these, reduced density gradient (RDG) analysis is performed, and thermodynamic features are carried out theoretically. The NMR spectra (1H and 13C) are calculated by using the gauge-invariant atomic orbital (GIAO) method. The vibrational spectra of 2,5-DFA molecule are obtained by using DFT/B3LYP method with 6-311++G(d,p) basis set. Fundamental vibrations are assigned based on the potential energy distribution (PED) of the vibrational modes. The nonlinear optical properties (NLO) are also investigated. The theoretical and experimental results give a detailed description of

  16. Exposure to PM2.5 and Blood Lead Level in Two Populations in Ulaanbaatar, Mongolia.

    PubMed

    Enkhbat, Undarmaa; Rule, Ana M; Resnick, Carol; Ochir, Chimedsuren; Olkhanud, Purevdorj; Williams, D'Ann L

    2016-02-01

    Approximately 60% of the households in Ulaanbaatar live in gers (a traditional Mongolian dwelling) in districts outside the legal limits of the city, without access to basic infrastructure, such as water, sewage systems, central heating, and paved roads, in contrast to apartment residents. This stark difference in living conditions creates different public health challenges for Ulaanbaatar residents. Through this research study we aim to test our hypothesis that women living in gers burning coal in traditional stoves for cooking and heating during the winter are exposed to higher concentrations of airborne PM2.5 than women living in apartments in Ulaanbaatar, Mongolia, and this exposure may include exposures to lead in coal with effects on blood lead levels. This cross-sectional study recruited a total of 50 women, 40-60 years of age, from these two settings. Air sampling was carried out during peak cooking and heating times, 5:00 p.m.-11:00 p.m., using a direct-reading instrument (TSI SidePak™) and integrated polytetrafluoroethylene (PTFE) filters using the SKC Personal Environmental Monitor. Blood lead level (BLL) was measured using a LeadCare II rapid field test method. In our study population, measured PM2.5 geometric mean (GM) concentrations using the SidePak™ in the apartment group was 31.5 (95% CI:17-99) μg/m³, and 100 (95% CI: 67-187) μg/m³ in ger households (p < 0.001). The GM integrated gravimetric PM2.5 concentrations in the apartment group were 52.8 (95% CI: 39-297) μg/m³ and 127.8 (95% CI: 86-190) μg/m³ in ger households (p = 0.004). The correlation coefficient for the SidePak™ PM2.5 concentrations and filter based PM2.5 concentrations was r = 0.72 (p < 0.001). Blood Lead Levels were not statistically significant different between apartment residents and ger residents (p = 0.15). The BLL is statistically significant different (p = 0.01) when stratified by length of exposures outside of the home. This statistically significant difference

  17. 'Superplane!' High Speed Civil Transport (pt 2/5)

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The High Speed Civil Transport (HSCT). This light-hearted promotional piece explains what the HSCT 'Superplane!' is and what advantages it will have over current aircraft. As envisioned, the HSCT is a next-generation supersonic (faster than the speed of sound) passenger jet that would fly 300 passengers at more than 1,500 miles per hour -- more than twice the speed of sound. It will cross the Pacific or Atlantic in less than half the time of modern subsonic jets, and at a ticket price less than 20 percent above comparable, slower flights

  18. Life after Adolescent and Adult Moderate and Severe Traumatic Brain Injury: Self-Reported Executive, Emotional, and Behavioural Function 2-5 Years after Injury.

    PubMed

    Finnanger, Torun Gangaune; Olsen, Alexander; Skandsen, Toril; Lydersen, Stian; Vik, Anne; Evensen, Kari Anne I; Catroppa, Cathy; Håberg, Asta K; Andersson, Stein; Indredavik, Marit S

    2015-01-01

    Survivors of moderate-severe Traumatic Brain Injury (TBI) are at risk for long-term cognitive, emotional, and behavioural problems. This prospective cohort study investigated self-reported executive, emotional, and behavioural problems in the late chronic phase of moderate and severe TBI, if demographic characteristics (i.e., age, years of education), injury characteristics (Glasgow Coma Scale score, MRI findings such as traumatic axonal injury (TAI), or duration of posttraumatic amnesia), symptoms of depression, or neuropsychological variables in the first year after injury predicted long-term self-reported function. Self-reported executive, emotional, and behavioural functioning were assessed among individuals with moderate and severe TBI (N = 67, age range 15-65 years at time of injury) 2-5 years after TBI, compared to a healthy matched control group (N = 72). Results revealed significantly more attentional, emotional regulation, and psychological difficulties in the TBI group than controls. Demographic and early clinical variables were associated with poorer cognitive and emotional outcome. Fewer years of education and depressive symptoms predicted greater executive dysfunction. Younger age at injury predicted more aggressive and rule-breaking behaviour. TAI and depressive symptoms predicted Internalizing problems and greater executive dysfunction. In conclusion, age, education, TAI, and depression appear to elevate risk for poor long-term outcome, emphasising the need for long-term follow-up of patients presenting with risk factors. PMID:26549936

  19. Fine particulate matter components and emergency department visits among a privately insured population in Greater Houston.

    PubMed

    Liu, Suyang; Ganduglia, Cecilia M; Li, Xiao; Delclos, George L; Franzini, Luisa; Zhang, Kai

    2016-10-01

    Although adverse health effects of PM2.5 (particulate matter with aerodynamic diameter less than 2.5μm) mass have been extensively studied, it remains unclear regarding which PM2.5 components are most harmful. No studies have reported the associations between PM2.5 components and adverse health effects among a privately insured population. In our study, we estimated the short-term associations between exposure to PM2.5 components and emergency department (ED) visits for all-cause and cause-specific diseases in Greater Houston, Texas, during 2008-2013 using ED visit data extracted from a private insurance company (Blue Cross Blue Shield Texas [BCBSTX]). A total of 526,453 ED visits were included in our assessment, with an average of 236 (±63) visits per day. We selected 20 PM2.5 components from the U.S. Environmental Protection Agency's Chemical Speciation Network site located in Houston, and then applied Poisson regression models to assess the previously mentioned associations. Interquartile range increases in bromine (0.003μg/m(3)), potassium (0.048μg/m(3)), sodium ion (0.306μg/m(3)), and sulfate (1.648μg/m(3)) were statistically significantly associated with the increased risks in total ED of 0.71% (95% confidence interval (CI): 0.06, 1.37%), 0.71% (95% CI: 0.21, 1.22%), 1.28% (95% CI: 0.34, 2.24%), and 1.22% (95% CI: 0.23, 2.23%), respectively. Seasonal analysis suggested strongest associations occurred during the warm season. Our findings suggest that a privately insured population, presumably healthier than the general population, may be still at risk of adverse health effects due to exposure to ambient PM2.5 components. PMID:27235902

  20. Chemical characterization, the transport pathways and potential sources of PM2.5 in Shanghai: Seasonal variations

    NASA Astrophysics Data System (ADS)

    Zhao, Mengfei; Huang, Zhongsi; Qiao, Ting; Zhang, Yuankai; Xiu, Guangli; Yu, Jianzhen

    2015-05-01

    The 24-h PM2.5 samples were collected at the site of East China University of Science and Technology (ECUST) in Shanghai from 2011 to 2012, representing winter, spring, summer and autumn, respectively. And PM2.5 and its chemical components including organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), humic-like substance carbon (HULIS-C) and water-soluble ions were analyzed. The results suggested that the average PM2.5 concentrations were (70.35 ± 43.75) μg/m3, (69.76 ± 38.67) μg/m3, (51.26 ± 28.25) μg/m3 and (82.37 ± 48.70) μg/m3 in winter, spring, summer and autumn, respectively. Secondary inorganic ions (sulfate, nitrate and ammonium) were the dominant pollutants of PM2.5 in the four seasons. Total carbon (TC) was an important component explaining above 15% of PM2.5. OC/EC ratios were all above 2 ranging from 4.31 to 6.35; particularly in winter it reached the highest 6.35 which demonstrated that secondary organic carbon (SOC) should be a significant composition of PM2.5. The SOC calculated based on the OC/EC ratio method had stronger correlation with WSOC in summer and autumn (summer: R2 = 0.73 and autumn: R2 = 0.75). The HULIS-C and SOC most significantly correlated in autumn (R2 = 0.83). The data showed that PM2.5 atmospheric aerosols were more acidic in autumn and the concentrations of PM2.5 and its chemical components were much higher. Factor analysis (FA), cluster analysis of air mass back trajectories, potential source contribution function (PSCF) model and concentration weighted trajectory (CWT) model were used to investigate the transport pathways and identify potential source areas of PM2.5 in different seasons. FA identified various sources of PM2.5: secondary aerosol reactions, the aged sea salts and road dusts. The results of cluster analysis, PSCF model and CWT model demonstrated that the local sources in the Yangtze River Delta Region (YRDR) made significant contributions to PM2.5. During winter and autumn long-time

  1. A statistical model to evaluate the effectiveness of PM2.5 emissions control during the Beijing 2008 Olympic Games.

    PubMed

    Liu, Yang; He, Kebin; Li, Shenshen; Wang, Zhaoxi; Christiani, David C; Koutrakis, Petros

    2012-09-01

    A statistical model was developed using satellite remote sensing data and meteorological parameters to evaluate the effectiveness of air pollution control measures during the 2008 Beijing Olympic Games. Custom satellite retrievals under hazy conditions were included in the modeling dataset to represent the air pollution levels more accurately. This model explained 70% of the PM(2.5) variability during the modeling period from June to October 2008. Using this tool, we estimate that the aggressive emission reduction measures alone effectively lowered PM(2.5) levels by 20-24 μg/m(3) or 27-33% on average during the Games period, which is substantially greater than those reported previously. Since parameters required to develop this model are readily available in most cities of the world, it can be quickly applied after other major events to evaluate air pollution control policy. PMID:22406019

  2. Tautomerism of 4-hydroxy-2,5-dimethyl-3(2H)-furanone: evidence for its enantioselective biosynthesis.

    PubMed

    Raab, Thomas; Hauck, Tobias; Knecht, Anja; Schmitt, Ulrich; Holzgrabe, Ulrike; Schwab, Wilfried

    2003-08-01

    Chiral natural flavor compounds exhibit characteristic enantiomeric excesses due to stereoselective, enzymatically catalyzed reactions during biogenesis. Although the enzymatic formation of the strawberry key flavor compound 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF; Furaneol(R)) is anticipated, the naturally occurring compound is racemic. As racemization due to keto-enol-tautomerism of HDMF could account for this observation, HDMF was investigated by (1)H-NMR spectroscopy tracing the exchange of the proton bound to the furanone-ring at C2 with deuteron from the medium (D(2)O). In addition, the racemization rate of HDMF was directly determined by cyclodextrin-modified capillary electrophoresis of enantiomerically enriched HDMF stored at different pH values. Tautomerism and the racemization rate of HDMF was lowest at pH values between 4 and 5. However, tautomerism and thus racemization was catalyzed under stronger acidic conditions (pH 2) and especially at pH values greater than 7, the value published for plant cell cytosol. Approximately 50% of the protons at C2 were exchanged with deuteron within 1 h at pH 7.2. Therefore, in order to demonstrate the enzymatic formation of HDMF, incubation experiments with Zygosaccharomyces rouxii as well as strawberry protein extract were carried out under slightly acidic conditions (pH 5), the most suitable pH value for studies on the enantiomeric ratio of HDMF. In both experiments the formation of enantiomerically enriched HDMF could be demonstrated for the first time, whereas incubation experiments under neutral conditions resulted in the detection of racemic HDMF. PMID:12840820

  3. Effects of the Particulate Matter2.5 (PM2.5) on Lipoprotein Metabolism, Uptake and Degradation, and Embryo Toxicity.

    PubMed

    Kim, Jae-Yong; Lee, Eun-Young; Choi, Inho; Kim, Jihoe; Cho, Kyung-Hyun

    2015-12-31

    Particulate matter2.5 (PM2.5) is notorious for its strong toxic effects on the cardiovascular, skin, nervous, and reproduction systems. However, the molecular mechanism by which PM2.5 aggravates disease progression is poorly understood, especially in a water-soluble state. In the current study, we investigated the putative physiological effects of aqueous PM2.5 solution on lipoprotein metabolism. Collected PM2.5 from Seoul, Korea was dissolved in water, and the water extract (final 3 and 30 ppm) was treated to human serum lipoproteins, macrophages, and dermal cells. PM2.5 extract resulted in degradation and aggregation of high-density lipoprotein (HDL) as well as low-density lipoprotein (LDL); apoA-I in HDL aggregated and apo-B in LDL disappeared. PM2.5 treatment (final 30 ppm) also induced cellular uptake of oxidized LDL (oxLDL) into macrophages, especially in the presence of fructose (final 50 mM). Uptake of oxLDL along with production of reactive oxygen species was accelerated by PM2.5 solution in a dose-dependent manner. Further, PM2.5 solution caused cellular senescence in human dermal fibroblast cells. Microinjection of PM2.5 solution into zebrafish embryos induced severe mortality accompanied by impairment of skeletal development. In conclusion, water extract of PM2.5 induced oxidative stress as a precursor to cardiovascular toxicity, skin cell senescence, and embryonic toxicity via aggregation and proteolytic degradation of serum lipoproteins. PMID:26615830

  4. Effects of the Particulate Matter2.5 (PM2.5) on Lipoprotein Metabolism, Uptake and Degradation, and Embryo Toxicity

    PubMed Central

    Kim, Jae-Yong; Lee, Eun-Young; Choi, Inho; Kim, Jihoe; Cho, Kyung-Hyun

    2015-01-01

    Particulate matter2.5 (PM2.5) is notorious for its strong toxic effects on the cardiovascular, skin, nervous, and reproduction systems. However, the molecular mechanism by which PM2.5 aggravates disease progression is poorly understood, especially in a water-soluble state. In the current study, we investigated the putative physiological effects of aqueous PM2.5 solution on lipoprotein metabolism. Collected PM2.5 from Seoul, Korea was dissolved in water, and the water extract (final 3 and 30 ppm) was treated to human serum lipoproteins, macrophages, and dermal cells. PM2.5 extract resulted in degradation and aggregation of high-density lipoprotein (HDL) as well as low-density lipoprotein (LDL); apoA-I in HDL aggregated and apo-B in LDL disappeared. PM2.5 treatment (final 30 ppm) also induced cellular uptake of oxidized LDL (oxLDL) into macrophages, especially in the presence of fructose (final 50 mM). Uptake of oxLDL along with production of reactive oxygen species was accelerated by PM2.5 solution in a dose-dependent manner. Further, PM2.5 solution caused cellular senescence in human dermal fibroblast cells. Microinjection of PM2.5 solution into zebrafish embryos induced severe mortality accompanied by impairment of skeletal development. In conclusion, water extract of PM2.5 induced oxidative stress as a precursor to cardiovascular toxicity, skin cell senescence, and embryonic toxicity via aggregation and proteolytic degradation of serum lipoproteins. PMID:26615830

  5. Greater Burgan of Kuwait: world's second largest oil field

    SciTech Connect

    Youash, Y.Y.

    1989-03-01

    Greater Burgan (Main burgan, Magwa, and Ahmadi) field is located in the Arabian Platform geologic province and the stable shelf tectonic environment of the Mesopotamian geosyncline, a sedimentary basin extending from the Arabian shield on the west to the complexly folded and faulted Zagros Mountains on the east. The structural development in Cretaceous time represents a major anticlinorium bounded by a basin to the west and a synclinorium to the east. Greater Burgan is located within this anticlinorium. The field consists of three dome structures 25 km wide and 65 km long with gentle dips of only few degrees. Faults have little throw and did not contribute to the trapping mechanism. The structural deformation may have been caused by halokinetic movements and most likely by basement block faulting that may have started in the Paleozoic. Greater Burgan was discovered in 1938. All production during the last 40 years has been by its natural pressure. Although natural gas injection has been carried out for some time, no waterflooding has been initiated yet. Recoverable reserves of the field are 87 billion bbl of oil. During the last 5 years giant reserves have been added in this field from the deeper strata of Jurassic age. Several deep wells have been drilled to the Permian for the purpose of discovering gas. So far, no Permian gas has been found in Kuwait. The Permian is 25,000 ft deep, and it is unlikely gas will be found there in the future. However, the potential of the Jurassic reservoirs will be a major target in the future. Also, there is a great possibility of discovering oil in stratigraphic traps, as several producing strata in the nearby fields pinch out on the flanks of this giant structure. Enhanced oil recovery should add significant reserves in the future.

  6. Personal exposures and microenvironment concentrations of PM 2.5, VOC, NO 2 and CO in Oxford, UK

    NASA Astrophysics Data System (ADS)

    Lai, H. K.; Kendall, M.; Ferrier, H.; Lindup, I.; Alm, S.; Hänninen, O.; Jantunen, M.; Mathys, P.; Colvile, R.; Ashmore, M. R.; Cullinan, P.; Nieuwenhuijsen, M. J.

    Between 1998 and 2000 in Oxford, UK, simultaneous personal exposures and microenvironmental measurements (home indoor, home outdoor and work indoor) to fine particulate matters PM 2.5, volatile organic compounds (VOC), nitrogen dioxide (NO 2) and carbon monoxide (CO) were carried out once per person among 50 adults over a 48-h period. Thirty-seven elements in PM 2.5 and 30 different VOCs were analysed. Questionnaires were distributed to record their time-activity patterns and exposure-related information. Results showed that participants spent more time (89.5%) in all indoors than in other microenvironments. Geometric mean (GM) of personal and home indoor levels of PM 2.5, 14 elements (aluminium, arsenic, bromine, calcium, copper, iron, gallium, potassium, sodium, phosphorus, lead, selenium, silicon, titanium), total VOC (TVOC) and 8 individual compounds (nonane, decane, undecane, trimethylbenzene, toluene, benzaldehyde, alpha-pinene and d-limonene) were over 20% higher than their GM outdoor levels. Those of NO 2, 5 aromatic VOCs (benzene, o-xylene, ethylbenzene, propylbenzene, m, p-xylene) and 5 other elements (chlorine, magnesium, manganese, sulphur, zinc) were close to their GM outdoor levels. For PM 2.5 and TVOC, personal exposures and residential indoor levels (in GM) were about 2 times higher among the tobacco-smoke exposed group compared to the non-smoke exposed group, suggesting that smoking is an important determinant of these exposures. Determinants for CO were visualised by real-time monitoring, and we showed that the peak levels of personal exposure to CO were associated with smoking, cooking and transportation activities. Moderate to good correlations were only found between the personal exposures and residential indoor levels for both PM 2.5 ( r=0.60, p<0.001) and NO 2 ( r=0.47, p=0.003).

  7. MULTI-SITE EVALUATIONS OF CANDIDATE METHODOLOGIES FOR DETERMINING COARSE PARTICULATE (PM 10-2.5) CONCENTRATIONS: AUGUST 2005 UPDATED REPORT REGARDING SECOND-GENERATION AND NEW PM 10-2.5 SAMPLERS

    EPA Science Inventory

    Multi-site field studies were conducted to evaluate the performance of sampling methods for measuring the coarse fraction of PM10 (PM10 2.5) in ambient air. The field studies involved the use of both time-integrated filter-based and direct continuous methods. Despite operationa...

  8. Effects of day-of-week trends and vehicle types on PM2.5-bounded carbonaceous compositions.

    PubMed

    Pongpiachan, Siwatt; Kositanont, Charnwit; Palakun, Jittree; Liu, Suixin; Ho, Kin Fai; Cao, Junji

    2015-11-01

    Carbonaceous compositions of PM2.5 were measured in the heart of Bangkok from 17th November 2010 to 19th January 2012, and a data set of 94 samples was constructed. Effects of day-of-week trends and vehicle types on PM2.5-bound TC, OC, and EC were carefully investigated. In this study, OC was the most important contributor to the total PM2.5 mass concentration. The average PM2.5-bound OC content measured at CHAOS (18.8 ± 9.18 μg m(-3)) was approximately 11 times higher than at Chaumont, Switzerland (1.7 μg m(-3)), but approximately five times lower than at Xi'an, China (93.0 μg m(-3)). The application of diagnostic binary ratios of OC/EC and estimations of secondary organic carbon (SOC) coupled with autocorrelation plots (Box and Jenkins) highlight the enhanced impacts of traffic emissions, especially from diesel vehicles, on PM2.5-bound carbonaceous compositions on weekdays relative to weekends. Hierarchical cluster analysis (HCA) coupled with principal component analysis (PCA) underline the importance of diesel emissions as the primary contributors of carbonaceous aerosols, particularly during weekdays. PMID:26100727

  9. Combined lint cleaning system PM2.5 emission factors and rates for cotton gins: Method 201A combination PM10 and PM2.5 sizing cyclones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of stack sampling. In 2006, EPA finalized and published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This created an urgent need to collect additi...

  10. Cyclone robber system PM2.5 emission factors and rates for cotton gins: Method 201A combination PM10 and PM2.5 sizing cyclones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of stack sampling. In 2006, EPA finalized and published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This created an urgent need to collect additi...

  11. Mote cyclone robber system PM2.5 emission factors and rates for cotton gins: Method 201A combination PM10 and PM2.5 sizing cyclones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of stack sampling. In 2006, the Environmental Protection Agency (EPA) finalized and published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This cr...

  12. Equating Semi-Continuous (SC) PM2.5 Mass Monitor Measurement Values with Federal Reference Method (FRM) PM2.5 Monitor Measurement Values

    EPA Science Inventory

    The effects of fine particulate matter (PM2.5) on human health are well documented (Pope et al., 2002). In order to spatially and temporally assess the impact of PM2.5 on the U.S. population, the U.S. Environmental Protection Agency (U.S. EPA) operates a ne...

  13. Master trash system PM2.5 emission factors and rates for cotton gins: Method 201A combination PM10 and PM2.5 sizing cyclones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of stack sampling. In 2006, the Environmental Protection Agency (EPA) finalized and published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This cr...

  14. Combined mote system PM2.5 emission factors and rates for cotton gins: Method 201A combination PM10 and PM2.5 sizing cyclones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of stack sampling. In 2006, the Environmental Protection Agency (EPA) finalized and published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This cr...

  15. Overflow system PM2.5 emission factors and rates for cotton gins: Method 201A combination PM10 and PM2.5 sizing cyclones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of stack sampling. In 2006, the Environmental Protection Agency (EPA), finalized and published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This c...

  16. First stage mote system PM2.5 emission factors and rates for cotton gins: Method 201A combination PM10 and PM2.5 sizing cyclones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions using stack sampling. In 2006, the Environmental Protection Agency (EPA) finalized and published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This created an urgent n...

  17. Mote cleaner system PM2.5 emission factors and rates for cotton gins: Method 201A combination PM10 and PM2.5 sizing cyclones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of stack sampling. In 2006, EPA finalized and published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This created an urgent need to collect additi...

  18. Battery condenser system PM2.5 emission factors and rates for cotton gins: Method 201A combination PM10 and PM2.5 sizing cyclones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of stack sampling. In 2006, EPA finalized and published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This created an urgent need to collect additi...

  19. Mote trash system PM2.5 emission factors and rate for cotton gins: Method 201A combination PM10 and PM2.5 sizing cyclones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of stack sampling. In 2006, the Environmental Protection Agency (EPA) finalized and published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This cr...

  20. RELAP5 assessment: LOFT large break L2-5

    SciTech Connect

    Thompson, S L; Kmetyk, L N

    1984-02-01

    RELAP5 is part of an effort to determine the ability of various systems codes to predict the detailed thermal/hydraulic response of LWRs during accident and off-normal conditions. The RELAP5 code is being assessed at SNLA against test data from various integral and separate effects test facilities. As part of this assessment matrix, a large break transient performed at the LOFT facility has been analyzed. The results show that RELAP5/MOD1 correctly calculates many of the major system variables (i.e., pressure, break flows, peak clad temperature) early in a large break LOCA. The major problems encountered in the analyses were incorrect pump coastdown and loop seal clearing early in the calculation, excessive pump speedup later in the transient (probably due to too much condensation-induced pressure drop at the ECC injection point), and excess ECC bypass calculated throughout the later portions of the test; only the latter problem significantly affected the overall results. This excess ECC bypass through the downcomer and vessel-side break resulted in too-large late-time break flows and high system pressure due to prolonged choked flow conditions. It also resulted in a second core heatup being calculated after the accumulator emptied, since water was not being retained in the vessel. Analogous calculations with a split-downcomer nodalization delivered some ECC water to the lower plenum, which was then swept up the core and upper plenum and out the other (pump-side) break; thus no significant differences in long-term overall behavior were evident between the calculations.

  1. Suicide in married couples in Sweden: Is the risk greater in same-sex couples?

    PubMed

    Björkenstam, Charlotte; Andersson, Gunnar; Dalman, Christina; Cochran, Susan; Kosidou, Kyriaki

    2016-07-01

    Minority sexual orientation is a predictor of suicide ideation and attempts, though its association with suicide mortality is less clear. We capitalize on Sweden's extensively linked databases, to investigate whether, among married individuals, same-sex marriage is associated with suicide. Using a population-based register design, we analyzed suicide risk among same-sex married women and men (n = 6456), as compared to different-sex married women and men (n = 1181723) in Sweden. We selected all newly partnered or married individuals in the intervening time between 1/1/1996 and 12/31/2009 and followed them with regard to suicide until 12/31/2011. Multivariate Poisson regression was used to calculate adjusted incidence risk ratios (IRR) with 95 % confidence intervals (CI). The risk of suicide was higher among same-sex married individuals as compared to different-sex married individuals (IRR 2.7, 95 % CI 1.5-4.8), after adjustment for time at risk and socioeconomic confounding. Sex-stratified analyses showed a tentatively elevated risk for same-sex married women (IRR 2.5, 95 % CI 0.8-7.7) as compared to different-sex married women. Among same-sex married men the suicide risk was nearly three-fold greater as compared to different-sex married (IRR 2.895 % CI 1.5-5.5). This holds true also after adjustment for HIV status. Even in a country with a comparatively tolerant climate regarding homosexuality such as Sweden, same-sex married individuals evidence a higher risk for suicide than other married individuals. PMID:27168192

  2. Final Technical Report. Results of Phases 2-5

    SciTech Connect

    Narang, David; Ayyanar, Raja; Gemin, Paul; Baggu, Murali; Srinivasan, Devarajan

    2015-02-27

    APS’s renewable energy portfolio, driven in part by Arizona’s Renewable Energy Standard (RES) currently includes more than 1100 MW of installed capacity, equating to roughly 3000 GWh of annual production. Overall renewable production is expected to grow to 6000 GWh by 2025. It is expected that distributed photovoltaics, driven primarily by lower cost, will contribute to much of this growth and that by 2025, distributed installations will account for half of all renewable production (3000GHW). As solar penetration increases, additional analysis may be required for routine utility processes to ensure continued safe and reliable operation of the electric distribution network. Such processes include residential or commercial interconnection requests and load shifting during normal feeder operations. Circuits with existing high solar penetration will also have to be studied and results will need to be evaluated for adherence to utility practices or strategy. Increased distributed PV penetration may offer benefits such as load offsetting, but it also has the potential to adversely impact distribution system operation. These effects may be exacerbated by the rapid variability of PV production. Detailed effects of these phenomena in distributed PV applications continue to be studied. Comprehensive, high-resolution electrical models of the distribution system were developed to analyze the impacts of PV on distribution circuit protection systems (including coordination and anti-islanding), predict voltage regulation and phase balance issues, and develop volt/VAr control schemes. Modeling methods were refined by validating against field measurements. To augment the field measurements, methods were developed to synthesize high resolution load and PV generation data to facilitate quasi-static time series simulations. The models were then extended to explore boundary conditions for PV hosting capability of the feeder and to simulate common utility practices such as feeder

  3. 2.5D Modeling of TEM Data Applied to Hidrogeological Studies in PARANÁ Basin, Brazil

    NASA Astrophysics Data System (ADS)

    Bortolozo, C. A.; Porsani, J. L.; Santos, F. M.

    2013-12-01

    The transient electromagnetic method (TEM) is used all over the world and has shown great potential in hydrological, hazardous waste site characterization, mineral exploration, general geological mapping, and geophysical reconnaissance. However, the behavior of TEM fields are very complex and is not yet fully understood. Forward modeling is one of the most common and effective methods to understand the physical behavior and significance of the electromagnetics responses of a TEM sounding. Until now, there are a limited number of solutions for the 2D forward problem for TEM. More rare are the descriptions of a three-component response of a 3D source over 2D earth, which is the so-called 2.5D. The 2.5D approach is more realistic than the conventional 2D source previous used, once normally the source cannot be realistic represented for a 2D approximation (normally source are square loops). At present the 2.5D model represents the only way of interpreting TEM data in terms of a complex earth, due to the prohibitive amount of computer time and storage required for a full 3D model. In this work we developed a TEM modeling program for understanding the different responses and how the magnetic and electric fields, produced by loop sources at air-earth interface, behave in different geoelectrical distributions. The models used in the examples are proposed focusing hydrogeological studies, once the main objective of this work is for detecting different kinds of aquifers in Paraná sedimentary basin, in São Paulo State - Brazil. The program was developed in MATLAB, a widespread language very common in the scientific community.

  4. Ultrafine particles, and PM 2.5 generated from cooking in homes

    NASA Astrophysics Data System (ADS)

    Wan, Man-Pun; Wu, Chi-Li; Sze To, Gin-Nam; Chan, Tsz-Chun; Chao, Christopher Y. H.

    2011-11-01

    Exposure to airborne particulate matters (PM) emitted during cooking can lead to adverse health effects. An understanding of the exposure to PM during cooking at home provides a foundation for the quantification of possible health risks. The concentrations of airborne particles covering the ultrafine (14.6-100 nm) and accumulation mode (100-661.2 nm) size ranges and PM 2.5 (airborne particulate matters smaller than 2.5 μm in diameter) during and after cooking activities were measured in 12 naturally ventilated, non-smoking homes in Hong Kong, covering a total of 33 cooking episodes. The monitored homes all practiced Chinese-style cooking. Cooking elevated the average number concentrations of ultrafine particles (UFPs) and accumulation mode particles (AMPs) by 10 fold from the background level in the living room and by 20-40 fold in the kitchen. PM 2.5 mass concentrations went up to the maximum average of about 160 μg m -3 in the kitchen and about 60 μg m -3 in the living room. Cooking emitted particles dispersed quickly from the kitchen to the living room indicating that the health impact is not limited to occupants in the kitchen. Particle number and mass concentrations remained elevated for 90 min in the kitchen and for 60 min in the living room after cooking. Particles in cooking emissions were mainly in the ultrafine size range in terms of the number count while AMPs contributed to at least 60% of the surface area concentrations in the kitchen and 73% in the living room. This suggests that AMPs could still be a major health concern since the particle surface area concentration is suggested to have a more direct relationship with inhalation toxicity than with number concentration. Particle number concentration (14.6-661.2 nm) in the living room was about 2.7 times that in the outdoor environment, suggesting that better ventilation could help reduce exposure.

  5. Statistical analysis of PM2.5 observations from diplomatic facilities in China

    NASA Astrophysics Data System (ADS)

    San Martini, Federico M.; Hasenkopf, Christa A.; Roberts, David C.

    2015-06-01

    Systematic monitoring of air quality are lacking in many parts of the world, especially in cities where air quality is poor. Since 2008, the U.S. Embassy in Beijing has been collecting real-time air-quality data from a monitor on the Embassy's rooftop and sharing that data publicly through social media. Using this freely available data, as well as those from four other U.S. consulates in China that are also now collecting and sharing data publicly, we demonstrate that rooftop air-quality monitors installed at embassies and consulates can further our understanding of air quality and provide a rich, hourly-averaged, long-term data source for the academic community and decision-makers. For example, this is the first study to present an analysis of diurnal variability of PM2.5 in Chengdu, Guangzhou, Shanghai, and Shenyang. We analyzed the diurnal variability of PM2.5 over the entire period of measurement for those cities and Beijing, and found marked variation across seasons and between cities. This dataset allows comparison of the PM2.5 annual average concentrations in 2013, with Guangzhou reporting 56.3 μg/m3, Shanghai 61.6 μg/m3, Chengdu 96.1 μg/m3, Beijing 99.6 μg/m3, and Shenyang 76.3 μg/m3 (note the average in Shenyang is from August 2013-July 2014). This study demonstrates the potential uses of air quality data that is currently systematically being collected and made publicly accessible by U.S. embassies and consulates in polluted but under-studied locations.

  6. Polar organic tracers in PM2.5 aerosols from forests in eastern China

    NASA Astrophysics Data System (ADS)

    Wang, W.; Wu, M. H.; Li, L.; Zhang, T.; Liu, X. D.; Feng, J. L.; Li, H. J.; Wang, Y. J.; Sheng, G. Y.; Claeys, M.; Fu, J. M.

    2008-12-01

    Photooxidation products of biogenic volatile organic compounds, mainly isoprene and monoterpenes, are significant sources of atmospheric particulate matter in forested regions. The objectives of this study were to examine time series and diel variations of polar organic tracers for the photooxidation of isoprene and α-pinene to investigate whether they are linked with meteorological parameters or trace gases, and to determine their carbon contributions. In addition, the biogenic secondary organic carbon contributions from isoprene were estimated. PM2.5 (particulate matter with an aerodynamic diameter <2.5 μm) aerosol samples were collected from forests in eastern China and compared with data from forested sites in Europe and America. Aerosol sampling was conducted at four sites located along a gradient of ecological succession in four different regions, i.e. Changbai Mountain Nature Reserve (boreal-temperate), Chongming National Forest Park (temperate), Dinghu Mountain Nature Reserve (subtropical) and Jianfengling Nature Reserve in Hainan (tropical) during summer periods when the meteorological conditions are believed to be favorable for photochemical processes. Fifty PM2.5 samples were collected; eighteen organic compounds, organic carbon (OC), elemental carbon and trace gases were measured. Results indicate that the concentration trends of the secondary organic compounds reflected those of the trace gases and meteorological parameters. Very good correlations between the sum concentrations of isoprene oxidation products and atmospheric SO2, O3, NO2, NOx, as well as CO2, at the Changbai site were found. The secondary OC due to isoprene was relatively high in tropical Hainan (0.27 μgC/m3) where isoprene-emitting broadleaf species are dominant, but was comparable in boreal Changbai (0.32 μgC/m3) where coniferous species are prevalent. The contribution of malic acid, which may have both biogenic and anthropogenic sources, to the OC mass was comparable at the four

  7. Compositional characterization of PM 2.5 emitted from in-use diesel vehicles

    NASA Astrophysics Data System (ADS)

    Kim Oanh, Nguyen Thi; Thiansathit, Worrarat; Bond, Tami C.; Subramanian, R.; Winijkul, Ekbordin; Paw-armart, Ittipol

    2010-01-01

    In Asian developing countries diesel vehicles contribute significantly to urban air pollution. The emission factors (EF) and exhaust gas composition of these vehicles may be different from those in the US and Europe, where most emission measurements are taken. This study focuses on the fine particulate matter (PM 2.5) emission from in-use diesel vehicles in Bangkok, with the goal of providing EF and source profiles that are more appropriate for developing countries. The chassis dynamometer test results for 93 vehicles, including 39 light duty (LD) and 54 heavy duty (HD) of the age models between 1972 and 2005, are presented. PM EF are lower for vehicles of newer year models, consistent with the implementation of engine standards. The average PM 2.5 EF of 0.23 g km -1 for LD, and 1.76 g km -1 for HD trucks and buses are generally higher than the literature reported values. Old HD trucks produce the highest PM EF of above 3 g km -1. Black carbon (BC), measured by an optical method, is well correlated with elemental carbon (EC) by TOT, but is consistently about 1.7 times higher. Between the LD and HD fleets, there is no significant difference in the fractional composition (BC, EC, OC, water soluble ions and elements) of emitted PM 2.5. The composite source profile, weighted against the fleet composition and the vehicle km travelled (VKT) for the city has an average OC of 19%, EC of 47%, and sulfate of 2%, which are close to those reported for 1980s US diesel vehicles.

  8. Dust monitoring on the Hanford Site: An investigation into the relationship between TSP, PM-10 and PM-2.5

    SciTech Connect

    Schwartz, Tara L.; Fritz, Brad G.

    2004-12-01

    Samples were collected to determine TSP concentration in air on the central plateau of the Hanford Site. These were compared to PM-10 and PM-2.5 data collected over the same time period. Results provide a means to estimate TSP concentration based on PM-10 concentration.

  9. EVALUATION OF SEVERAL PM 2.5 FORECAST MODELS USING DATA COLLECTED DURING THE ICARTT/NEAQS 2004 FIELD STUDY

    EPA Science Inventory

    Real-time forecasts of PM2.5 aerosol mass from seven air-quality forecast models (AQFMs) are statistically evaluated against observations collected in the northeastern U.S. and southeastern Canada from two surface networks and aircraft data during the summer of 2004 IC...

  10. Reversible photoresponsive switching in Bi(2.5)Na(0.5)Nb(2)O(9)-based luminescent ferroelectrics.

    PubMed

    Zhang, Qiwei; Sun, Haiqin; Li, Hao; Wang, Xusheng; Hao, Xihong; Song, Jinling; An, Shengli

    2015-11-25

    Reversible luminescence modulation upon photochromic reactions with excellent reproducibility was achieved from Eu(3+) doped Bi2.5Na0.5Nb2O9 multifunctional ferroelectrics. The material exhibits strong sensitivity to visible light or sunlight with fast response time without inducing any structural changes. PMID:26390220

  11. TASK 2.5.5 NATURAL EXPOSURE TESTING IN CALIFORNIA

    SciTech Connect

    Miller, William A; Cheng, Mengdawn; New, Joshua Ryan; Ronnen, Levinson; Akbari, Hashem; Berhahl, Paul

    2010-03-01

    Airborne particulate matter that settles on a roof can either reflect or absorb incoming solar radiation, dependent on the chemical content and size of the particles. These light scattering and absorption processes occur within a few microns of the surface, and can affect the solar reflectance of the roof. Wilkes et al. (2000) tested 24 different roof coatings on a low-slope test stand and observed about a 25% decrease in the solar reflectance of white-coated and aluminum-coated surfaces as the time of exposure increased; however, the decrease leveled off after 2 years. SPRI Inc. and its affiliates studied the effect of climatic exposure on the surface properties of white thermoplastic single-ply membranes and determined that membranes lose from 30 to 50% of their reflectance over 3 years (Miller et al. 2002). The CMRC and its affiliates AISI, NamZAC, MBMA, MCA and NCCA exposed unpainted and painted metal roofing on both steep- and low-slope test roofs and found that after 3 years, the painted polyvinylidene fluoride (PVDF) metal roofs lost less than 5% of their original reflectance (Miller et al. 2004). The results of the three different weathering studies are very interesting in terms of their solar reflectance after 3 years of exposure. The white thermoplastic membrane and white ceramic coating with white topcoat had original reflectance measures that were about 20 percentage points higher than the painted metal; however, after 3-years of field exposure the solar reflectance of the painted metal exceeds that of the thermoplastic membrane and equals that of the coating. The long-term loss of reflectance appears driven by the ability of the particulate matter to cling to the roof and resist being washed off by wind and or rain. Miller et al. (2002) discovered that aerosol deposition introduced biomass of complex microbial consortia onto the test roofs and the combination of contaminants and biomass accelerated the loss of solar reflectance for the thermoplastic

  12. Fracture characteristics of Ti-6Al-4V and Ti-5Al-2.5Fe with refined microstructure using hydrogen

    NASA Astrophysics Data System (ADS)

    Niinomi, M.; Gong, B.; Kobayashi, T.; Ohyabu, Y.; Toriyama, O.

    1995-05-01

    The hydrogenation behavior of Ti-6Al-4V, with the starting microstructures of coarse equiaxed α and coarse Widmanstätten α, respectively, was investigated under a hydrogen pressure of 0.1 MPa at temperatures between 843 and 1123 K. The hydrogen content was determined as a function of hydrogenation time, hydrogenation temperature, and hydrogen flow rate. The phases presented in the alloy of after hydrogenation were determined with X-ray and electron diffraction analysis in order to define the effect of Thermochemical Processing (TCP) on the microstructure of the alloy. Mechanical properties and fracture toughness of Ti-6Al-4V and Ti-5Al-2.5Fe subjected to the various TCP were then investigated. Hydrogenation of Ti-6Al-4V with the starting microstructure of coarse equiaxed α at 1023 K, just below hydrogen saturated β (denoted β″ (H)) transus temperature, produces a microstructure of a, orthohombic martensite (denoted α″ (H)) and β (H). Hydrogenation at 1123 K, above β (H) transus, results in a microstructure of α″ (H) and β (H). Microstructure refinement during TCP results mainly from decomposition of α″ (H) and ;β (H) into a fine mixture of α + β during dehydrogenation. An alternative TCP method is below β (H) transus hydrogenation (BTH), consisting of hydrogenation of the alloy below the hydrogenated β (H) transus temperature, air cooling to room temperature, and dehydrogenation at a lower temperature, which is found to improve mechanical properties significantly over a conventional TCP treatment. Compared with the untreated material, the BTH treatment increases the yield strength and increases the ultimate tensile strength significantly without decreasing the tensile elongation in the starting microstructure of coarse equiaxed α or with a little decrease in the tensile elongation in the starting microstructure of coarse Widmanstätten α, although the conventional TCP treatment results in a large decrease in elongation over the

  13. Television viewing through ages 2-5 years and bullying involvement in early elementary school

    PubMed Central

    2014-01-01

    Background High television exposure time at young age has been described as a potential risk factor for developing behavioral problems. However, less is known about the effects of preschool television on subsequent bullying involvement. We examined the association between television viewing time through ages 2-5 and bullying involvement in the first grades of elementary school. We hypothesized that high television exposure increases the risk of bullying involvement. Method TV viewing time was assessed repeatedly in early childhood using parental report. To combine these repeated assessments we used latent class analysis. Four exposure classes were identified and labeled “low”, “mid-low”, “mid-high” and “high”. Bullying involvement was assessed by teacher questionnaire (n = 3423, mean age 6.8 years). Additionally, peer/self-report of bullying involvement was obtained using a peer nomination procedure (n = 1176, mean age 7.6 years). We examined child risk of being a bully, victim or a bully-victim (compared to being uninvolved in bullying). Results High television exposure class was associated with elevated risks of bullying and victimization. Also, in both teacher- and child-reported data, children in the high television exposure class were more likely to be a bully-victim (OR = 2.11, 95% CI: 1.42-3.13 and OR = 3.68, 95% CI: 1.75-7.74 respectively). However, all univariate effect estimates attenuated and were no longer statistically significant once adjusted for maternal and child covariates. Conclusions The association between television viewing time through ages 2-5 and bullying involvement in early elementary school is confounded by maternal and child socio-demographic characteristics. PMID:24520886

  14. A quantitative analysis of grid nudging effect on each process of PM2.5 production in the Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Jeon, Wonbae; Choi, Yunsoo; Lee, Hwa Woon; Lee, Soon-Hwan; Yoo, Jung-Woo; Park, Jaehyeong; Lee, Hyo-Jung

    2015-12-01

    This study investigated the effect of assimilated meteorological fields on simulated PM2.5 concentrations in the Korean Peninsula. Two different CMAQ simulations were conducted using base WRF run (BASE) and grid-nudged WRF run (GNG) which included a simple data assimilation method for the time period of April, 2009. The simulated PM2.5 and PM10 concentrations were compared with corresponding observations. The BASE PM2.5 concentrations were significantly underestimated at Anmyeondo (AMD) and six Air Quality Monitoring Station (AQMS) sites in Korea, but GNG showed improved agreement with in-situ measurements due to the effect of grid nudging. The grid nudging effect was dominant under the PBL height and it appeared more clearly under the unstable synoptic condition (April 5-8) than stable condition (April 9-13). Additional quantitative analysis was conducted using the Integrated Process Rate (IPR) in the CMAQ model to investigate the effect of varied meteorological fields on each PM2.5 production and destruction processes. The PM2.5 production rate by aerosol process in GNG was shown to be higher than that of BASE, especially near the source region (e.g., Eastern China). The increased temperature and decreased wind speed by grid nudging effect led to increase of aerosol production rates especially during the nighttime. The change of aerosol production rates were mainly caused by increased sulfate (SO42-) and nitrate (NO3-) production rates in the day and nighttime respectively. Also, GNG provides higher PM2.5 transport rates than BASE over the whole domain. The amount of PM2.5 scavenged by wet deposition process in GNG was smaller than that of BASE over the Yellow Sea, reflecting the decreased water vapor mixing ratio by grid nudging. Thus, it resulted in the increase of simulated PM2.5 concentrations. The results indicated that understanding the effects of grid nudging on PM2.5 concentrations is crucial to enhance the performance of PM2.5 modeling

  15. Characterization of the chemical composition of PM2.5 emitted from on-road China III and China IV diesel trucks in Beijing, China.

    PubMed

    Wu, Bobo; Shen, Xianbao; Cao, Xinyue; Yao, Zhiliang; Wu, Yunong

    2016-05-01

    The composition of diesel exhaust fine particulate matter (PM2.5) is of growing interest because of its impacts on health and climatic factors and its application in source apportionment and aerosol modeling. We characterized the detailed chemical composition of the PM2.5, including the organic carbon (OC), elemental carbon (EC), water-soluble ions (WSIs), and elemental contents, emitted from China III and China IV diesel trucks (nine each) based on real-world measurements in Beijing using a portable emissions measurement system (PEMS). Carbonaceous compounds were the dominant components (totaling approximately 87%) of the PM2.5, similar to the results (greater than 80% of the PM2.5) of our previous study of on-road China III diesel trucks. In general, the amounts of individual component groups (carbonaceous compounds, WSIs, and elements) and PM2.5 emissions for China IV diesel trucks were lower than those of China III diesel trucks of the same size, except for the WSIs and elements for the light- and medium-duty diesel trucks. The EC/OC mass ratios were strongly dependent on the emission standards, and the ratios of China IV diesel trucks were higher than those of China III diesel trucks of the same size. The chemical species in the PM2.5 were significantly affected by the driving conditions. Overall, the emission factors (EFs) of the PM2.5 and OC under non-highway (NHW) driving conditions were higher than those under highway (HW) driving conditions, and the EC/OC mass ratios presented an increasing trend, with decreasing OC/PM2.5 and increasing EC/PM2.5 from NHW to HW driving conditions; similar trends were reported in our previous study. In addition, Pearson's correlation coefficients among the PM2.5 species were analyzed to determine the relationships among the various chemical components. PMID:26897401

  16. Variations in nanomechanical properties of back-end Zr-2.5Nb pressure tube material

    NASA Astrophysics Data System (ADS)

    Gallaugher, Matthew; Peykov, Daniel; Brodusch, Nicolas; Chromik, Richard R.; Rodrigue, Lisa; Trudeau, Michel L.; Gauvin, Raynald

    2013-11-01

    The Zr-2.5Nb pressure tube alloy used in Canada Deuterium Uranium (CANDU) nuclear reactors consists of a dual-phase microstructure produced by a multi-step manufacturing process. The metallurgical characteristics of the pressure tubes influence their in-reactor behavior, especially with respect to reactor life-limiting properties such as diametral creep. In order to predict the in-reactor behavior of pressure tubes, a greater understanding of the influence of tube-to-tube variations in metallurgical factors such as texture, grain size, and β-phase percentage would be greatly beneficial. In this paper, a testing method combining high temperature nanoindentation with subsequent electron channeling contrast imaging (ECCI) in the scanning electron microscope (SEM) is presented to compare two back end pressure tube off-cuts. Nanoindentation was used to measure local mechanical properties such as hardness, modulus, and strain rate sensitivity. Post-examination of residual indents with ECCI allowed for the correlation of microstructural characteristics to nanomechanical properties. A difference in hardness was observed between the two tubes in the axial normal plane, which was correlated to differences in β-phase area percentage and/or morphology.

  17. 40 CFR 52.1602 - Control strategy and regulations: PM2.5.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy and regulations: PM2.5... Control strategy and regulations: PM2.5. (a) Approval—On May 18, 2006, New Jersey submitted an early PM2.5... New Jersey-Long Island, NY-NJ-CT, PM2.5 nonattainment area. The budgets were allocated by...

  18. 40 CFR 52.1602 - Control strategy and regulations: PM2.5.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Control strategy and regulations: PM2.5... Control strategy and regulations: PM2.5. (a) Approval—On May 18, 2006, New Jersey submitted an early PM2.5... New Jersey-Long Island, NY-NJ-CT, PM2.5 nonattainment area. The budgets were allocated by...

  19. 40 CFR 52.1602 - Control strategy and regulations: PM2.5.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Control strategy and regulations: PM2.5... Control strategy and regulations: PM2.5. (a) Approval—On May 18, 2006, New Jersey submitted an early PM2.5... New Jersey-Long Island, NY-NJ-CT, PM2.5 nonattainment area. The budgets were allocated by...

  20. 40 CFR 52.1602 - Control strategy and regulations: PM2.5.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Control strategy and regulations: PM2.5... Control strategy and regulations: PM2.5. (a) Approval—On May 18, 2006, New Jersey submitted an early PM2.5... New Jersey-Long Island, NY-NJ-CT, PM2.5 nonattainment area. The budgets were allocated by...

  1. 40 CFR 52.1602 - Control strategy and regulations: PM2.5.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Control strategy and regulations: PM2.5... Control strategy and regulations: PM2.5. (a) Approval—On May 18, 2006, New Jersey submitted an early PM2.5... New Jersey-Long Island, NY-NJ-CT, PM2.5 nonattainment area. The budgets were allocated by...

  2. Collocated comparisons of continuous and filter-based PM2.5 measurements at Fort McMurray, Alberta, Canada

    PubMed Central

    Hsu, Yu-Mei; Wang, Xiaoliang; Chow, Judith C.; Watson, John G.; Percy, Kevin E.

    2016-01-01

    ABSTRACT Collocated comparisons for three PM2.5 monitors were conducted from June 2011 to May 2013 at an air monitoring station in the residential area of Fort McMurray, Alberta, Canada, a city located in the Athabasca Oil Sands Region. Extremely cold winters (down to approximately −40°C) coupled with low PM2.5 concentrations present a challenge for continuous measurements. Both the tapered element oscillating microbalance (TEOM), operated at 40°C (i.e., TEOM40), and Synchronized Hybrid Ambient Real-time Particulate (SHARP, a Federal Equivalent Method [FEM]), were compared with a Partisol PM2.5 U.S. Federal Reference Method (FRM) sampler. While hourly TEOM40 PM2.5 were consistently ~20–50% lower than that of SHARP, no statistically significant differences were found between the 24-hr averages for FRM and SHARP. Orthogonal regression (OR) equations derived from FRM and TEOM40 were used to adjust the TEOM40 (i.e., TEOMadj) and improve its agreement with FRM, particularly for the cold season. The 12-year-long hourly TEOMadj measurements from 1999 to 2011 based on the OR equations between SHARP and TEOM40 were derived from the 2-year (2011–2013) collocated measurements. The trend analysis combining both TEOMadj and SHARP measurements showed a statistically significant decrease in PM2.5 concentrations with a seasonal slope of −0.15 μg m−3 yr−1 from 1999 to 2014.Implications: Consistency in PM2.5 measurements are needed for trend analysis. Collocated comparison among the three PM2.5 monitors demonstrated the difference between FRM and TEOM, as well as between SHARP and TEOM. The orthogonal regressions equations can be applied to correct historical TEOM data to examine long-term trends within the network. PMID:26727574

  3. PM2.5 analog forecast and Kalman filter post-processing for the Community Multiscale Air Quality (CMAQ) model

    NASA Astrophysics Data System (ADS)

    Djalalova, Irina; Delle Monache, Luca; Wilczak, James

    2015-10-01

    A new post-processing method for surface particulate matter (PM2.5) predictions from the National Oceanic and Atmospheric Administration (NOAA) developmental air quality forecasting system using the Community Multiscale Air Quality (CMAQ) model is described. It includes three main components: A real-time quality control procedure for surface PM2.5 observations; Model post-processing at each observational site using historical forecast analogs and Kalman filtering; Spreading the forecast corrections from the observation locations to the entire gridded domain.

  4. Long-term PM2.5 Exposure and Neurological Hospital Admissions in the Northeastern United States

    PubMed Central

    Kioumourtzoglou, Marianthi-Anna; Schwartz, Joel D.; Weisskopf, Marc G.; Melly, Steven J.; Wang, Yun; Dominici, Francesca; Zanobetti, Antonella

    2015-01-01

    Background Long-term exposure to fine particles (particulate matter ≤ 2.5 μm; PM2.5) has been consistently linked to heart and lung disease. Recently, there has been increased interest in examining the effects of air pollution on the nervous system, with evidence showing potentially harmful effects on neurodegeneration. Objective Our objective was to assess the potential impact of long-term PM2.5 exposure on event time, defined as time to first admission for dementia, Alzheimer’s (AD), or Parkinson’s (PD) diseases in an elderly population across the northeastern United States. Methods We estimated the effects of PM2.5 on first hospital admission for dementia, AD, and PD among all Medicare enrollees ≥ 65 years in 50 northeastern U.S. cities (1999–2010). For each outcome, we first ran a Cox proportional hazards model for each city, adjusting for prior cardiopulmonary-related hospitalizations and year, and stratified by follow-up time, age, sex, and race. We then pooled the city-specific estimates by employing a random effects meta-regression. Results We followed approximately 9.8 million subjects and observed significant associations of long-term PM2.5 city-wide exposure with all three outcomes. Specifically, we estimated a hazard ratio (HR) of 1.08 (95% CI: 1.05, 1.11) for dementia, an HR of 1.15 (95% CI: 1.11, 1.19) for AD, and an HR of 1.08 (95% CI: 1.04, 1.12) for PD admissions per 1-μg/m3 increase in annual PM2.5 concentrations. Conclusions To our knowledge, this is the first study to examine the relationship between long-term exposure to PM2.5 and time to first hospitalization for common neurodegenerative diseases. We found strong evidence of association for all three outcomes. Our findings provide the basis for further studies, as the implications of such exposures could be crucial to public health. Citation Kioumourtzoglou MA, Schwartz JD, Weisskopf MG, Melly SJ, Wang Y, Dominici F, Zanobetti A. 2016. Long-term PM2.5 exposure and neurological

  5. Estimating Causal Effects of Long-Term PM2.5 Exposure on Mortality in New Jersey

    PubMed Central

    Wang, Yan; Kloog, Itai; Coull, Brent A.; Kosheleva, Anna; Zanobetti, Antonella; Schwartz, Joel D.

    2016-01-01

    Background: Many studies have reported the associations between long-term exposure to PM2.5 and increased risk of death. However, to our knowledge, none has used a causal modeling approach or controlled for long-term temperature exposure, and few have used a general population sample. Objective: We estimated the causal effects of long-term PM2.5 exposure on mortality and tested the effect modifications by seasonal temperatures, census tract–level socioeconomic variables, and county-level health conditions. Methods: We applied a variant of the difference-in-differences approach, which serves to approximate random assignment of exposure across the population and hence estimate a causal effect. Specifically, we estimated the association between long-term exposure to PM2.5 and mortality while controlling for geographical differences using dummy variables for each census tract in New Jersey, a state-wide time trend using dummy variables for each year from 2004 to 2009, and mean summer and winter temperatures for each tract in each year. This approach assumed that no variable changing differentially over time across space other than seasonal temperatures confounded the association. Results: For each interquartile range (2 μg/m3) increase in annual PM2.5, there was a 3.0% [95% confidence interval (CI): 0.2, 5.9%] increase in all natural-cause mortality for the whole population, with similar results for people > 65 years old [3.5% (95% CI: 0.1, 6.9%)] and people ≤ 65 years old [3.1% (95% CI: –1.8, 8.2%)]. The mean summer temperature and the mean winter temperature in a census tract significantly modified the effects of long-term exposure to PM2.5 on mortality. We observed a higher percentage increase in mortality associated with PM2.5 in census tracts with more blacks, lower home value, or lower median income. Conclusions: Under the assumption of the difference-in-differences approach, we identified a causal effect of long-term PM2.5 exposure on mortality that was

  6. Sexual predators, energy development, and conservation in greater Yellowstone.

    PubMed

    Berger, Joel; Beckmann, Jon P

    2010-06-01

    In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies-recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)-differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in-migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems. PMID:20184654

  7. A FUNCTIONAL GROUP CHARACTERIZATION OF ORGANIC PM 2.5 EXPOSURE: RESULTS FROM THE RIOPA STUDY

    EPA Science Inventory

    The functional group (FG) composition of urban residential outdoor, indoor, and personal fine particle (PM2.5) samples is presented and used to provide insights relevant to organic PM2.5 exposure. PM2.5 samples (48 h) were collected during the Rel...

  8. 9 CFR 2.5 - Duration of license and termination of license.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Duration of license and termination of license. 2.5 Section 2.5 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Licensing § 2.5 Duration of license and termination...

  9. 10 CFR 960.3-2-2-5 - Formal site nomination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Formal site nomination. 960.3-2-2-5 Section 960.3-2-2-5 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3-2-2-5 Formal site nomination. After the...

  10. 10 CFR 960.3-2-2-5 - Formal site nomination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Formal site nomination. 960.3-2-2-5 Section 960.3-2-2-5 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3-2-2-5 Formal site nomination. After the...

  11. STRUCTURE OF PRIMARY PM2.5 DERIVED FROM DIESEL TRUCK EXHAUST

    EPA Science Inventory

    The U.S. Environmental Protection Agency is currently considering regulations on airborne particulate matter < 2.5 microns in mean diameter (PM2.5). It is important that the molecular structure and microstructure of PM2.5 from various sources be thoroughly characterized in order ...

  12. AN OVERVIEW OF PM2.5 SOURCES AND CONTROL STRATEGIES

    EPA Science Inventory

    The new national ambient air quality standard for particulate matter is summarized, with emphasis on fine particles, or PM2.5 (particulate matter with aerodynamic diameter less than 2.5 micrometers). Sources of ambient and indoor PM2.5 are summarized, followed by an overview of c...

  13. 32 CFR 2.5 - Criteria for designation of participating programs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 1 2014-07-01 2014-07-01 false Criteria for designation of participating programs. 2.5 Section 2.5 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE ACQUISITION PILOT PROGRAM POLICY § 2.5 Criteria for designation of participating programs. (a) Candidate programs must have an approved requirement,...

  14. 9 CFR 2.5 - Duration of license and termination of license.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Duration of license and termination of license. 2.5 Section 2.5 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Licensing § 2.5 Duration of license and termination...

  15. APPLICATION GUIDE FOR MEASUREMENT OF PM2.5 AT STATIONARY SOURCES

    EPA Science Inventory

    This manual presents two options which allow determination of stationary source PM2.5 to be measured in conjunction with PM10 and it can be measured as PM2.5 only. hen determining both PM2.5 and PM10, either the Constant Sampling Rate (CSR) procedures or the Exhaust Gas Recycle (...

  16. Emissions Inventory of PM2.5 Trace Elements across the United States

    EPA Science Inventory

    This paper presents the first National Emissions Inventory (NEI) of fine particulate matter (PM2.5) that includes the full suite of PM2.5 trace elements (atomic number >10) measured at ambient monitoring sites across the U.S. PM 2.5 emissions in ...

  17. 43 CFR 2.5 - Does DOI maintain an index of its reading room materials?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Does DOI maintain an index of its reading room materials? 2.5 Section 2.5 Public Lands: Interior Office of the Secretary of the Interior RECORDS... a FOIA Request § 2.5 Does DOI maintain an index of its reading room materials? Each bureau...

  18. 10 CFR 960.3-2-2-5 - Formal site nomination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Formal site nomination. 960.3-2-2-5 Section 960.3-2-2-5 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3-2-2-5 Formal site nomination. After the...

  19. 10 CFR 960.3-2-2-5 - Formal site nomination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Formal site nomination. 960.3-2-2-5 Section 960.3-2-2-5 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3-2-2-5 Formal site nomination. After the...

  20. 10 CFR 960.3-2-2-5 - Formal site nomination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Formal site nomination. 960.3-2-2-5 Section 960.3-2-2-5 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3-2-2-5 Formal site nomination. After the...

  1. 41 CFR 102-2.5 - What is the Federal Management Regulation (FMR)?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Management Regulation (FMR)? 102-2.5 Section 102-2.5 Public Contracts and Property Management Federal Property Management Regulations System (Continued) FEDERAL MANAGEMENT REGULATION GENERAL 2-FEDERAL MANAGEMENT REGULATION SYSTEM Regulation System General § 102-2.5 What is the Federal Management...

  2. 40 CFR 50.18 - National primary ambient air quality standards for PM2.5.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... standards for PM2.5. 50.18 Section 50.18 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... primary ambient air quality standards for PM2.5. (a) The national primary ambient air quality standards for PM2.5 are 12.0 micrograms per cubic meter (µg/m3) annual arithmetic mean concentration and 35...

  3. 40 CFR 51.1008 - Emission inventory requirements for the PM2.5 NAAQS.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PM2.5 NAAQS. 51.1008 Section 51.1008 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Provisions for Implementation of PM2.5 National Ambient Air Quality Standards § 51.1008 Emission inventory requirements for the PM2.5 NAAQS. (a) For purposes of meeting the emission inventory requirements of...

  4. 78 FR 54177 - Adequacy Status of the Submitted 2009, 2017 and 2025 PM2.5

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-03

    ... York area had attained the 1997 (75 FR 69589) and 2006 (77 FR 76867) PM 2.5 NAAQS based on ambient air... transportation conformity determinations for analysis years prior to 2017. Table 1--PM2.5 Motor Vehicle Emissions... PM2.5 NOX Council 2009 Motor Vehicle Emissions Budget..... 5,516.75 106,020.09 2017 Motor...

  5. 40 CFR 51.1008 - Emission inventory requirements for the PM2.5 NAAQS.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PM2.5 NAAQS. 51.1008 Section 51.1008 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Provisions for Implementation of PM2.5 National Ambient Air Quality Standards § 51.1008 Emission inventory requirements for the PM2.5 NAAQS. (a) For purposes of meeting the emission inventory requirements of...

  6. 40 CFR 51.1008 - Emission inventory requirements for the PM2.5 NAAQS.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PM2.5 NAAQS. 51.1008 Section 51.1008 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Provisions for Implementation of PM2.5 National Ambient Air Quality Standards § 51.1008 Emission inventory requirements for the PM2.5 NAAQS. (a) For purposes of meeting the emission inventory requirements of...

  7. 40 CFR 51.1008 - Emission inventory requirements for the PM2.5 NAAQS.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PM2.5 NAAQS. 51.1008 Section 51.1008 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Provisions for Implementation of PM2.5 National Ambient Air Quality Standards § 51.1008 Emission inventory requirements for the PM2.5 NAAQS. (a) For purposes of meeting the emission inventory requirements of...

  8. 40 CFR 51.1008 - Emission inventory requirements for the PM2.5 NAAQS.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PM2.5 NAAQS. 51.1008 Section 51.1008 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Provisions for Implementation of PM2.5 National Ambient Air Quality Standards § 51.1008 Emission inventory requirements for the PM2.5 NAAQS. (a) For purposes of meeting the emission inventory requirements of...

  9. 40 CFR 50.18 - National primary ambient air quality standards for PM2.5.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... standards for PM2.5. 50.18 Section 50.18 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... primary ambient air quality standards for PM2.5. (a) The national primary ambient air quality standards for PM2.5 are 12.0 micrograms per cubic meter (µg/m3) annual arithmetic mean concentration and 35...

  10. 43 CFR 8365.2-5 - Public health, safety and comfort.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Public health, safety and comfort. 8365.2-5 Section 8365.2-5 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF... § 8365.2-5 Public health, safety and comfort. On developed recreation sites and areas, unless...

  11. 43 CFR 8365.2-5 - Public health, safety and comfort.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Public health, safety and comfort. 8365.2-5 Section 8365.2-5 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF... § 8365.2-5 Public health, safety and comfort. On developed recreation sites and areas, unless...

  12. Basic statistics of PM2.5 and PM10 in the atmosphere of Mexico City.

    PubMed

    Vega, E; Reyes, E; Sánchez, G; Ortiz, E; Ruiz, M; Chow, J; Watson, J; Edgerton, S

    2002-03-27

    The high levels of fine particulate matter in Mexico City are of concern since they may induce severe public health effects as well as the attenuation of visible light. Sequential filter samplers were used at six different sites from 23 February to 22 March 1997. The sampling campaign was carried out as part of the project 'Investigación sobre Materia Particulada y Deterioro Atmosferico-Aerosol and Visibility Evaluation Research'. This research was a cooperative project sponsored by PEMEX and by the US Department of Energy. Sampling sites represent the different land uses along the city, the northwest station, Tlalnepantla, is located in a mixed medium income residential and industrial area. The northeast station, Xalostoc, is located in a highly industrialized area, Netzahualcoyotl is located in a mixed land use area, mainly commercial and residential. Station La Merced is located in the commercial and administrative district downtown. The southwest station is located in the Pedregal de San Angel, in a high-income neighborhood, and the southeast station located in Cerro de la Estrella is a mixed medium income residential and commercial area. Samples were collected four times a day in Cerro de la Estrella (CES), La Merced (MER) and Xalostoc (XAL) with sampling periods of 6 h. In Pedregal (PED), Tlalnepantla (TLA) and Netzahualcoyot1 (NEZ) sampling periods were every 24 h. In this paper the basic statistics of PM2.5 and PM10 mass concentrations are presented. The average results showed that 49, 61, 46, 57, 51 and 44% of the PM10 consisted of PM2.5 for CES, MER, XAL, PED, TLA and NEZ, respectively. The 24-h average highest concentrations of PM25 and PM10 were registered at NEZ (184 and 267 microg/m3) and the lowest at PED (22 and 39 microg/m3). The highest PM10 correlations were between XAL-CES (0.79), PED-TLA (0.80). In contrast, the highest PM2.5 correlations were between CES-PED (0.74), MER-CES (0.73) and TLA-PED (0.72), showing a lower correlation than the PM10

  13. One-pot, one-step, catalytic synthesis of 2,5-diformylfuran from fructose

    NASA Astrophysics Data System (ADS)

    Tao, Furong; Cui, Yuezhi; Yang, Pengfei; Gong, Yinghua

    2014-07-01

    MIL-101, a chromium-based metal-organic framework, is known for its very large pore size, large surface area and good stability. However, application of this material in catalysis is still limited. In this paper, a simple and practical catalytic method for the preparation 2,5-diformylfuran (DFF) directly from fructose was investigated. 5% Pd-V(3: 2)@MIL-101 was evaluated as a potential and effective catalyst for the direct oxidation of fructose. The amount of the catalyst, reaction time and temperature had a large effect on the reaction. At the optimized reaction conditions, when the reaction was conducted at 140°C for 600 min, 1 atm oxygen pressure, the yield of DFF reached 34%, fructose conversion was up to 100%. In our system, the main side products were 5-formyl-2-furancarboxylic acid (FFCA) and 2,5-furandicarboxylic acid (FDCA), which are the products of deep oxidation of DFF. This simple and effective catalytic system may be valuable to facilitate energy-efficient conversion of fructose into biofuels and platform chemicals.

  14. CAQI Common Air Quality Index--update with PM(2.5) and sensitivity analysis.

    PubMed

    van den Elshout, Sef; Léger, Karine; Heich, Hermann

    2014-08-01

    The CAQI or Common Air Quality Index was proposed to facilitate the comparison of air quality in European cities in real-time. There are many air quality indices in use in the world. All are somewhat different in concept and presentation and comparing air quality presentations of cities on the internet was virtually impossible. The CAQI and the accompanying website www.airqualitynow.eu and app were proposed to overcome this problem in Europe. This paper describes the logic of making an index, in particular the CAQI and its update with a grid for PM2.5. To assure a smooth transition to the new calculation scheme we studied the behaviour of the index before and after the changes. We used 2006 Airbase data from 31 urban background and 27 street stations all across Europe (that were monitoring PM2.5 in 2006). The CAQI characterises a city by a roadside and urban background situation. It also insists on a minimum number of pollutants to be included in the calculation. Both were deemed necessary to improve the basis for comparing one city to another. A sensitivity analysis demonstrates the comparative behaviour of the street and urban background stations and presents the sensitivity of the CAQI outcome to the pollutants included in its calculation. PMID:24238948

  15. Nonlinear optical behavior of Li n F (n = 2-5) superalkali clusters.

    PubMed

    Srivastava, Ambrish Kumar; Misra, Neeraj

    2015-12-01

    Hyperlithiated clusters are known for their unusual bonding characteristics and lower ionization potentials. This study reports nonlinear optical (NLO) properties of a series of hyperlithiated clusters, Li n F (n = 2-5) for the first time. The structures of small Li n F (n = 2-5) clusters, obtained using second order Møller-Plesset perturbative method, are found to be stable against eliminations of F, F‾, and LiF. These Li n F species are stabilized by both ionic as well as covalent interactions. Our study shows that Li n F species can be thought of as superalkali-halogen (Li n  - F) clusters but belong to the class of superalkalies themselves. These clusters may also possess alkalide and/or electride characteristics due to excess electrons. The dipole moment, mean polarizability, and hyperpolarizability suggest their significant NLO responses which are explained using the highest occupied molecular orbital surfaces and TD-DFT analysis. The exceptionally large hyperpolarizability of Li2F (~10(5) a.u.) and its electride characteristics are particularly highlighted. This study may guide the researchers in the design of novel materials with significant NLO responses useful for electro-optical applications. Graphical Abstract Li2F superalkali resemble an electride in which the excess electron is pushed out by Li2 (+) moiety, leading to its high hyperpolarizability of order of 10(5) a.u. PMID:26546265

  16. Concentrations and chemical compositions of fine particles (PM2.5) during haze and non-haze days in Beijing

    NASA Astrophysics Data System (ADS)

    Zhang, Yang; Huang, Wei; Cai, Tianqi; Fang, Dongqing; Wang, Yuqin; Song, Jian; Hu, Min; Zhang, Yuanxun

    2016-06-01

    To investigate the chemical properties of PM2.5 and put forward reasonable control measures, daily samples of PM2.5 were collected at an urban site in Beijing from August 4 to September 3 of 2012 using two 2-channel samplers. Chemical analysis was conducted for eight water soluble inorganic ions (WSII, including Na+, NH4+, K+, Mg2 +, Ca2 +, Cl-, NO3-, and SO42 -), organic carbon (OC) and elementary carbon (EC). PM2.5 concentrations ranged from 8.8 to 218.6 μg m- 3, with an average concentration of 80.6 ± 57.3 μg m- 3. WSII, the most dominant PM2.5 constituents contributing 60 ± 18% of its mass, ranged from 3.1 to 172.2 μg m- 3. SO42 -, NO3-, and NH4+ dominated WSII (90 ± 28%) and their concentrations were 1.3-105.7 μg m- 3, 0.5-52.7 μg m- 3 and 0.3-33.5 μg m- 3, respectively. The concentrations of OC and EC were 3.0-28.8 μgC m- 3 and 0.8-7.4 μgC m- 3, constituting 17.6% and 4.9% of PM2.5, respectively. Three serious pollution episodes (haze days) occurred during the campaign. PM2.5 and its chemical species showed substantial increases during haze episodes. The greater enhancement factors for SO42 - (4.5), NO3- (4.0), and NH4+ (4.2) during haze days compared to non-haze days were obtained, suggesting that these secondary inorganic ions play important roles in the formation of haze. The average ratio of NO3-/SO42 - was 0.52. Ion balance calculations showed that PM2.5 samples were acidic during haze periods and close to neutral during non-haze days. Correlation analysis between the major ions was conducted and the results suggested that the main forms of NH4+ might be (NH4)2SO4. In addition, the variations between haze days and non-haze days for OC, EC, and the ratio of OC/EC were discussed.

  17. PM 2.5 and associated ionic component concentrations inside the archaeological museum of Thessaloniki, N. Greece

    NASA Astrophysics Data System (ADS)

    Mouratidou, Th.; Samara, C.

    PM 2.5 and its associated ionic component concentrations (Cl -, Br -, F -, NO 3-, NO 2-, SO 42-, HCOO -, CH 3COO -, H 2PO 4-, Na +, K +, NH 4+, Ca 2+, Mg 2+) were determined in the Archaeological Museum of Thessaloniki (AMT), in Northern Greece, where sculptures and other antiquities dated from the Archaic, Classical, Hellenistic and Roman times are displayed. Indoor and outdoor PM 2.5 samplings were concurrently carried out over a 3-month period. Both sites showed similar temporal variations with indoor PM 2.5 concentrations exceeding outdoor levels. Resuspension of soil dust particles introduced by visitors and restoration works carried out during sampling campaign were concluded as being major indoor sources for fine particles and associated calcium. Sulfate was found to be the dominant ion in indoor aerosol originating from external penetration rather than indoor sources. Increased indoor acidity was also observed resulting from the potential presence of partially neutralized ammonium sulfate.

  18. Chemical composition of PM2.5 particles in Salamanca, Guanajuato Mexico: Source apportionment with receptor models

    NASA Astrophysics Data System (ADS)

    Herrera Murillo, Jorge; Campos Ramos, Arturo; Ángeles García, Felipe; Blanco Jiménez, Salvador; Cárdenas, Beatriz; Mizohata, Akira

    2012-04-01

    The National Institute of Ecology, through Management General for Environmental Research and Training (DGCENICA) carried out a sampling campaign where a total of 21 elements were determined in 140 PM2.5 samples from one sampling site located in the city of Salamanca, Guanajuato-Mexico between November 2006 and November 2007. The annual average PM2.5 concentration was 45 μg/m3 almost three times the Mexican Annual standard for PM2.5. Mineral, organic and elemental carbon were the most important components present in particles PM2.5. Two advanced receptor models, UNMIX and positive matrix factorization (PMF) were used for PM2.5 source identification. Four and six sources were identified by UNMIX and PMF, respectively, from a combined dataset including 15 chemical species. Source categories were determined based on both, component abundances in the source profiles, and their temporal characteristics. Overall, different sources were identified as the major contributors: heavy fuels combustion, traditional brick production-agricultural burning, crustal, road traffic and secondary organic aerosols.

  19. Estimating adult mortality attributable to PM2.5 exposure in China with assimilated PM2.5 concentrations based on a ground monitoring network.

    PubMed

    Liu, Jun; Han, Yiqun; Tang, Xiao; Zhu, Jiang; Zhu, Tong

    2016-10-15

    Estimates of mortality attributable to air pollution in China showed large differences among various studies, mainly arising from differences in exposure assessments and choice of the concentration-response function. The Chinese national monitoring network recently has included direct measurements of PM2.5 (particulates with aerodynamic diameter≤2.5μm), providing a potentially more reliable exposure assessment. We estimated adult premature mortalities due to PM2.5 across China in 2013 and mortality benefits for scenarios in which China meets the World Health Organization (WHO) Air Quality Guidelines (AQG) and three interim targets (ITs) for PM2.5. Attributable adult mortalities were estimated with assimilated spatial PM2.5 concentrations across China based on direct PM2.5 measurements from 506 PM2.5 monitoring sites and a regional air quality model, and using the integrated exposure-response model. Our results show that in China, 83% of the population lived in areas where PM2.5 concentrations exceeded the Chinese Ambient Air Quality Standard of 35μgm(-3). Premature mortalities attributed to PM2.5 nationwide were 1.37 million in total, and 0.69, 0.38, 0.13, and 0.17 million for stroke, ischemic heart disease, lung cancer, and chronic obstructive pulmonary disease, respectively. High population density areas exhibited the highest health risks attributed to air pollution. The mortality benefits will be 23%, 39%, 66%, and 83% of the total present premature mortalities (1.37 million mortalities) when PM2.5 concentrations in China meet the WHO IT-1, IT-2, IT-3, and AQG, respectively. Our study shows that integrating PM2.5 concentrations based on the national monitoring network with the regional air quality model provides an advanced exposure estimate method with potentials to further improve the accuracy for mortality estimate; much higher health benefits could be achieved if China adopted more stringent WHO guidelines for PM2.5. PMID:27266521

  20. Greater focus needed on methane leakage from natural gas infrastructure.

    PubMed

    Alvarez, Ramón A; Pacala, Stephen W; Winebrake, James J; Chameides, William L; Hamburg, Steven P

    2012-04-24

    Natural gas is seen by many as the future of American energy: a fuel that can provide energy independence and reduce greenhouse gas emissions in the process. However, there has also been confusion about the climate implications of increased use of natural gas for electric power and transportation. We propose and illustrate the use of technology warming potentials as a robust and transparent way to compare the cumulative radiative forcing created by alternative technologies fueled by natural gas and oil or coal by using the best available estimates of greenhouse gas emissions from each fuel cycle (i.e., production, transportation and use). We find that a shift to compressed natural gas vehicles from gasoline or diesel vehicles leads to greater radiative forcing of the climate for 80 or 280 yr, respectively, before beginning to produce benefits. Compressed natural gas vehicles could produce climate benefits on all time frames if the well-to-wheels CH(4) leakage were capped at a level 45-70% below current estimates. By contrast, using natural gas instead of coal for electric power plants can reduce radiative forcing immediately, and reducing CH(4) losses from the production and transportation of natural gas would produce even greater benefits. There is a need for the natural gas industry and science community to help obtain better emissions data and for increased efforts to reduce methane leakage in order to minimize the climate footprint of natural gas. PMID:22493226

  1. Greater focus needed on methane leakage from natural gas infrastructure

    PubMed Central

    Alvarez, Ramón A.; Pacala, Stephen W.; Winebrake, James J.; Chameides, William L.; Hamburg, Steven P.

    2012-01-01

    Natural gas is seen by many as the future of American energy: a fuel that can provide energy independence and reduce greenhouse gas emissions in the process. However, there has also been confusion about the climate implications of increased use of natural gas for electric power and transportation. We propose and illustrate the use of technology warming potentials as a robust and transparent way to compare the cumulative radiative forcing created by alternative technologies fueled by natural gas and oil or coal by using the best available estimates of greenhouse gas emissions from each fuel cycle (i.e., production, transportation and use). We find that a shift to compressed natural gas vehicles from gasoline or diesel vehicles leads to greater radiative forcing of the climate for 80 or 280 yr, respectively, before beginning to produce benefits. Compressed natural gas vehicles could produce climate benefits on all time frames if the well-to-wheels CH4 leakage were capped at a level 45–70% below current estimates. By contrast, using natural gas instead of coal for electric power plants can reduce radiative forcing immediately, and reducing CH4 losses from the production and transportation of natural gas would produce even greater benefits. There is a need for the natural gas industry and science community to help obtain better emissions data and for increased efforts to reduce methane leakage in order to minimize the climate footprint of natural gas. PMID:22493226

  2. Black Carbon and Particulate Matter (PM2.5) Concentrations in New York City’s Subway Stations

    PubMed Central

    2015-01-01

    The New York City (NYC) subway is the main mode of transport for over 5 million passengers on an average weekday. Therefore, airborne pollutants in the subway stations could have a significant impact on commuters and subway workers. This study looked at black carbon (BC) and particulate matter (PM2.5) concentrations in selected subway stations in Manhattan. BC and PM2.5 levels were measured in real time using a Micro-Aethalometer and a PDR-1500 DataRAM, respectively. Simultaneous samples were also collected on quartz filters for organic and elemental carbon (OC/EC) analysis and on Teflon filters for gravimetric and trace element analysis. In the underground subway stations, mean real time BC concentrations ranged from 5 to 23 μg/m3, with 1 min average peaks >100 μg/m3, while real time PM2.5 levels ranged from 35 to 200 μg/m3. Mean EC levels ranged from 9 to 12.5 μg/m3. At street level on the same days, the mean BC and PM2.5 concentrations were below 3 and 10 μg/m3, respectively. This study shows that both BC soot and PM levels in NYC’s subways are considerably higher than ambient urban street levels and that further monitoring and investigation of BC and PM subway exposures are warranted. PMID:25409007

  3. Ethyl-2, 5-dihydroxybenzoate displays dual activity by promoting osteoblast differentiation and inhibiting osteoclast differentiation.

    PubMed

    Kwon, Byeong-Ju; Lee, Mi Hee; Koo, Min-Ah; Kim, Min Sung; Seon, Gyeung Mi; Han, Jae-Jin; Park, Jong-Chul

    2016-03-11

    The interplay between bone-forming osteoblasts and bone-resorbing osteoclasts is essential for balanced bone remodeling. In this study, we evaluate the ability of ethyl-2, 5-dihyrdoxybenzoate (E-2, 5-DHB) to affect both osteoblast and osteoclast differentiation for bone regeneration. Osteogenic differentiation of human mesenchymal stem cells (hMSCs) was quantified by measuring alkaline phosphatase (ALP) activity and calcium deposition. To evaluate osteoclast differentiation, we investigated the effect of E-2, 5-DHB on RANKL-activated osteoclastogenesis in RAW 264.7 cells. E-2, 5-DHB enhanced ALP activity and inhibited RAW 264.7 cell osteoclastogenesis in vitro. To assess the in vivo activity of E-2, 5-DHB, hMSCs were delivered subcutaneosuly alone or in combination with E-2, 5-DHB in an alginate gel into the backs of nude-mice. Histological and immunohistochemical evaluation showed significantly higher calcium deposition in the E-2, 5-DHB group. Osteocalcin (OCN) was highly expressed in cells implanted in the gels containing E-2, 5-DHB. Our results suggest that E-2, 5-DHB can effectively enhance osteoblast differentiation and inhibit osteoclast differentiation both in vitro and in vivo. Understanding the dual function of E-2, 5-DHB on osteoblast and osteoclast differentiation will aid in future development of E-2, 5-DHB as a material for bone tissue engineering. PMID:26869515

  4. Complex SUMO-1 Regulation of Cardiac Transcription Factor Nkx2-5

    PubMed Central

    Costa, Mauro W.; Lee, Stella; Furtado, Milena B.; Xin, Li; Sparrow, Duncan B.; Martinez, Camila G.; Dunwoodie, Sally L.; Kurtenbach, Eleonora; Mohun, Tim; Rosenthal, Nadia; Harvey, Richard P.

    2011-01-01

    Reversible post-translational protein modifications such as SUMOylation add complexity to cardiac transcriptional regulation. The homeodomain transcription factor Nkx2-5/Csx is essential for heart specification and morphogenesis. It has been previously suggested that SUMOylation of lysine 51 (K51) of Nkx2-5 is essential for its DNA binding and transcriptional activation. Here, we confirm that SUMOylation strongly enhances Nkx2-5 transcriptional activity and that residue K51 of Nkx2-5 is a SUMOylation target. However, in a range of cultured cell lines we find that a point mutation of K51 to arginine (K51R) does not affect Nkx2-5 activity or DNA binding, suggesting the existence of additional Nkx2-5 SUMOylated residues. Using biochemical assays, we demonstrate that Nkx2-5 is SUMOylated on at least one additional site, and this is the predominant site in cardiac cells. The second site is either non-canonical or a “shifting” site, as mutation of predicted consensus sites and indeed every individual lysine in the context of the K51R mutation failed to impair Nkx2-5 transcriptional synergism with SUMO, or its nuclear localization and DNA binding. We also observe SUMOylation of Nkx2-5 cofactors, which may be critical to Nkx2-5 regulation. Our data reveal highly complex regulatory mechanisms driven by SUMOylation to modulate Nkx2-5 activity. PMID:21931855

  5. Stereoselective Substrate-Controlled Asymmetric Syntheses of both 2,5-cis- and 2,5-trans-Tetrahydrofuranoid Oxylipids: Stereodivergent Intramolecular Amide Enolate Alkylation.

    PubMed

    Jang, Hongjun; Shin, Iljin; Lee, Dongjoo; Kim, Hyoungsu; Kim, Deukjoon

    2016-05-23

    The concise, highly stereoselective, substrate-controlled asymmetric total syntheses of both 2,5-cis- and 2,5-trans-tetrahydrofuranoid nematocidal oxylipids from the Australian brown algae Notheia anomala have been accomplished in a stereodivergent fashion. The highly stereoselective intramolecular amide enolate alkylation strategy provides access to both stereoisomers of the 3-hydroxy-2,5-disubstituted tetrahydrofuran core of these marine natural products through chelate and nonchelate control, which is driven by the C3-hydroxy protecting group. This approach offers an optional and highly stereoelective access to any of the eight possible stereoisomers of the 2,5-disubstituted-3-oxygenated tetrahydrofuran skeleton, an important structural feature which is present in many biologically active natural products. PMID:27100276

  6. Exposure of bakery and pastry apprentices to airborne flour dust using PM2.5 and PM10 personal samplers

    PubMed Central

    Mounier-Geyssant, Estelle; Barthélemy, Jean-François; Mouchot, Lory; Paris, Christophe; Zmirou-Navier, Denis

    2007-01-01

    Background This study describes exposure levels of bakery and pastry apprentices to flour dust, a known risk factor of occupational asthma. Methods Questionnaires on work activity were completed by 286 students. Among them, 34 performed a series of two personal exposure measurements using a PM2.5 and PM10 personal sampler during a complete work shift, one during a cold ("winter") period, and the other during a hot ("summer") period. Results Bakery apprentices experience greater average PM2.5 and PM10 exposures than pastry apprentices (p < 0.006). Exposure values for both particulate fractions are greater in winter (average PM10 values among bakers = 1.10 mg.m-3 [standard deviation: 0.83]) than in summer (0.63 mg.m-3 [0.36]). While complying with current European occupational limit values, these exposures exceed the ACGIH recommendations set to prevent sensitization to flour dust (0.5 mg.m-3). Over half the facilities had no ventilation system. Conclusion Young bakery apprentices incur substantial exposure to known airways allergens, a situation that might elicit early induction of airways inflammation. PMID:17976230

  7. Decreasing trends of suspended particulate matter and PM2.5 concentrations in Tokyo, 1990-2010.

    PubMed

    Hara, Kunio; Homma, Junichi; Tamura, Kenji; Inoue, Mariko; Karita, Kanae; Yano, Eiji

    2013-06-01

    In Tokyo, the annual average suspended particulate matter (SPM) and PM2.5 concentrations have decreased in the past two decades. The present study quantitatively evaluated these decreasing trends using data from air-pollution monitoring stations. Annual SPM and PM2.5 levels at 83 monitoring stations and hourly SPM and PM2.5 levels at four monitoring stations in Tokyo, operated by the Tokyo Metropolitan Government, were used for analysis, together with levels of co-pollutants and meteorological conditions. Traffic volume in Tokyo was calculated from the total traveling distance of vehicles as reported by the Ministry of Land, Infrastructure, Transport, and Tourism. High positive correlations between SPM levels and nitrogen oxide levels, sulfur dioxide levels, and traffic volume were determined. The annual average SPM concentration declined by 62.6%from 59.4 microg/m3 in 1994 to 22.2 microg/m3 in 2010, and PM2.5 concentration also declined by 49.8% from 29.3 microg/m3 in 2001 to 14.7 microg/m3 in 2010. Likewise, the frequencies of hourly average SPM and PM2.5 concentrations exceeding the daily guideline values have significantly decreased since 2001 and the hourly average SPM or PM2.5 concentrations per traffic volume for each time period have also significantly decreased since 2001. However SPM and PM2.5 concentrations increased at some monitoring stations between 2004 and 2006 and from 2009 despite strengthened environmental regulations and improvements in vehicle engine performance. The annual average SPM and PM2.5 concentrations were positively correlated with traffic volumes and in particular with the volume of diesel trucks. These results suggest that the decreasing levels of SPM and PM2.5 in Tokyo may be attributable to decreased traffic volumes, along with the effects of stricter governmental regulation and improvements to vehicle engine performance, including the fitting of devices for exhaust emission reduction. PMID:23858999

  8. 40 CFR Table C-4 to Subpart C of... - Test Specifications for PM 10, PM 2.5 and PM 10-2.5 Candidate Equivalent Methods

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Test Specifications for PM 10, PM 2.5 and PM 10-2.5 Candidate Equivalent Methods C Table C-4 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-4 Table C-4 to Subpart C of Part 53—Test Specifications for...

  9. 40 CFR Table C-4 to Subpart C of... - Test Specifications for PM 10, PM 2.5 and PM 10-2.5 Candidate Equivalent Methods

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Test Specifications for PM 10, PM 2.5 and PM 10-2.5 Candidate Equivalent Methods C Table C-4 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-4 Table C-4 to Subpart C of Part 53—Test Specifications for...

  10. Greater Athens PM pollution: Local or regional origin;

    NASA Astrophysics Data System (ADS)

    Pateraki, Stella; Maggos, Thomas; Assimakopoulos, Demosthenis; Bougiatioti, Aikaterini; Vasilakos, Christos; Mihalopoulos, Nikolaos

    2013-04-01

    During the last decades, the Particulate Matter (PM) pollution has become one of most challenging environmental problems worldwide. Along with their impact on global climate change and ecosystems, particles, especially for the smaller one, are indicated by numerous epidemiological studies to pose a great risk to human health with acute or long-term effects. Being located at the intersection of air masses circulating among three continents, the Mediterranean Basin is one of the areas heavily affected by aerosols with both natural and anthropogenic origin. Furthermore, the complex prevailing meteorology favours the aging of polluted air masses and induces high level of PM and photooxidant gases. In line with such scientific demands, the aim of the specific work is to elucidate the main characteristics of PM2.5 and PM1 nature (mass and chemical composition (Cl-, , SO , , K+, Mg2+, Ca2+, OC, EC)) of the Greater Athens Area (GAA) to elucidate the factors controlling the PM pollution and enable the policy makers to develop effective air quality remediation plans. Taking into consideration that PM measured at a specific site is the result of combined features and processes, at a local or a larger scale, as well as the air quality degradation by particulate matter over polluted areas which is often characterized by high levels of regional background aerosols, the main goal of this study is the identification and estimation of the local or regional contribution to the PM burden at GAA during different meteorological driven scenarios. Focusing on the changes in the prevailing atmospheric circulation patterns (mesoscale/synoptic wind regimes), a mass closure study of the available chemical species in conjunction with the observed PM mass is also attempted, in order to differentiate the relative contributions of the constituents. Special attention is also given to the high PM concentration (exceedances) days. The experimental campaign was held in parallel, during the period of

  11. Inhibition of light emission in a 2.5D photonic structure

    SciTech Connect

    Peretti, Romain; Seassal, Christian; Viktorovich, Pierre; Letartre, Xavier

    2014-07-14

    We analyse inhibition of emission in a 2.5D photonic structures made up of a photonic crystal (PhC) and Bragg mirrors using Finite Differences Time Domaine (FDTD) simulations. A comparison is made between an isolated PhC membrane and the same PhC suspended onto a Bragg mirror or sandwiched between 2 Bragg mirrors. Strong inhibition of the Purcell factor is observed in a broad spectral range, whatever the in-plane orientation and location of the emitting dipole. We analysed these results numerically and theoretically by simulating the experimentally observed lifetime of a collection of randomly distributed emitters, showing that their average emission rate is decreased by more than one decade, both for coupled or isolated emitters.

  12. 1s2s2p2 5p3 5S transition in B ii

    NASA Astrophysics Data System (ADS)

    Mannervik, S.; Cederquist, H.; Martinson, I.; Brage, T.; Froese Fischer, C.

    1987-04-01

    An experimental and theoretical study has been made of the 1s2s2p2 5P-1s2p3 5S transition in B ii. The experimental wavelength and lifetime (1323.92+/-0.07 Å and 0.65+/-0.01 ns), determined by beam-foil spectroscopy, are more than five times more accurate than previous experimental results. Our theoretical data, from multiconfiguration Hartree-Fock calculations, 1311.6 Å and 0.601 ns, are in excellent agreement with previous theoretical predictions of Beck and Nicolaides [Phys. Lett. 61A, 227 (1977)]. We have also observed the 1s2p3 5S-1s2p23s 5P transition, at 857.7+/-0.2 Å, in accord with the theoretical value 859.1 Å.

  13. Construction and testing of the 2.5m mass driver

    NASA Technical Reports Server (NTRS)

    Snow, W. R.; Oneill, G. K.

    1979-01-01

    Presented are the designs used in the construction of the 2.5 m mass driver and the results of the initial testing program. The mass driver consists of equal length sections of acceleration and deceleration each containing 59 drive coils of 13.1 cm caliber. Intermediate energy storage is provided by sector capacitors which are recharged every half cycle by an external power source. The drive coils are individually energized through SCR's with timing supplied by position sensing optical detectors. The drive consists of two phases which operate in quadrature. The initial bucket to be propelled through the mass driver contains two coils of aluminum wire chilled to liquid nitrogen temperatures to momentarily sustain superconducting field intensities. Magnetic flight is generated by eddy current repulsion from six copper guide strips lining the mass driver. Nominal acceleration is 5000 m/sec per sec giving a maximum bucket velocity of 112 m/s.

  14. Accumulation of 2',5'-oligoadenylates in encephalomyocarditis virus-infected mice.

    PubMed Central

    Hearl, W G; Johnston, M I

    1987-01-01

    Levels of 2',5'-oligoadenylates (2-5A) in various tissues of murine encephalomyocarditis virus (EMCV)-infected mice were determined and compared with those found in pathogen-free mice and in mice treated with the interferon inducer poly(I).poly(C). In control, pathogen-free mice, liver, spleen, brain, and kidney tissues possessed levels of 2-5A below 1 pmol/g of tissue, demonstrating that 2-5A was not a major component of uninfected mouse tissue. All control tissues had low basal levels (0.3 to 2.0 pmol/h per g) of 2-5A synthetase, the enzyme responsible for 2-5A production. After mice were injected intravenously with the interferon inducer poly(I).poly(C), circulating interferon, 2-5A synthetase, and 2-5A were elevated with increasing doses of double-stranded RNA. The greatest response to poly(I).poly(C) occurred in the kidney, in which enzyme levels increased 5-fold and 2-5A levels increased 24-fold to 15 pmol/g. Mice that were infected with EMCV also possessed elevated levels of 2-5A and 2-5A synthetase in the four tissues examined, although the relative distribution differed from that observed with poly(I).poly(C), indicating that the interferon inducer affects the concentration and location of intracellular 2-5A. Brain, spleen, and kidney tissues from EMCV-infected mice contained seven- to eightfold more 2-5A than control tissues did. The nanomolar levels of 2-5A in the tissues of EMCV-infected mice provide evidence that 2-5A may play a role in the antiviral response in an intact animal. In both poly(I).poly(C)- and EMCV-treated mice, the levels of 2-5A recovered from the tissues were not directly proportional to the amount of 2-5A synthetase present. These results indicate that factors other than the level of 2-5A synthetase controlled the accumulation of 2-5A in tissues. PMID:2437319

  15. Dry deposition of PM2.5 sulfate above a hilly forest using relaxed eddy accumulation

    NASA Astrophysics Data System (ADS)

    Matsuda, Kazuhide; Watanabe, Ichiro; Mizukami, Kou; Ban, Satomi; Takahashi, Akira

    2015-04-01

    Sulfur compounds continue to be an important component of atmospheric deposition in East Asia. In order to better understand the dry deposition of PM2.5 sulfate, which is one of the most significant transboundary air pollutants in this region, we measured the dry deposition flux of PM2.5 sulfate above a hilly forest of the Field Museum Tamakyuryo (FM Tama) site in suburban Tokyo. We used the relaxed eddy accumulation (REA) method and took measurements during the summer, from 26 July to 2 August 2013, and the autumn, from 18 to 22 November 2013. We primarily focused on the evaluation of dry deposition above a forest on complex terrain. The total flux and 80% of the runs showed downward flux. The deposition velocities measured by the REA method during times when the wind direction was from a relatively uniform sloping surface over the forest were more reasonable than those measured when the wind direction was from a more complex surface. Using a resistance model that includes the effect of growth of hygroscopic aerosols, we inferred the deposition velocities during two experimental periods. When the fluxes were averaged for a long time (i.e., about 2 weeks) the inferred fluxes and deposition velocities were in reasonable agreement with the measurements. Although averages over long periods showed good agreement, the measured deposition velocities were distributed in a wider range than those inferred by the model. An increased range of deposition velocities was associated with flux footprints from complex terrain. It is possible that the agreements between measured and inferred fluxes or deposition velocities at the site are because the depositions of sulfate are largely controlled by surface factors rather than aerodynamic resistance.

  16. Selective cytotoxicity of PAMAM G5 core–PAMAM G2.5 shell tecto-dendrimers on melanoma cells

    PubMed Central

    Schilrreff, Priscila; Mundiña-Weilenmann, Cecilia; Romero, Eder Lilia; Morilla, Maria Jose

    2012-01-01

    Background The controlled introduction of covalent linkages between dendrimer building blocks leads to polymers of higher architectural order known as tecto-dendrimers. Because of the few simple steps involved in their synthesis, tecto-dendrimers could expand the portfolio of structures beyond commercial dendrimers, due to the absence of synthetic drawbacks (large number of reaction steps, excessive monomer loading, and lengthy chromatographic separations) and structural constraints of high-generation dendrimers (reduction of good monodispersity and ideal dendritic construction due to de Gennes dense-packing phenomenon). However, the biomedical uses of tecto-dendrimers remain unexplored. In this work, after synthesizing saturated shell core–shell tecto-dendrimers using amine-terminated polyamidoamine (PAMAM) generation 5 (G5) as core and carboxyl-terminated PAMAM G2.5 as shell (G5G2.5 tecto-dendrimers), we surveyed for the first time the main features of their interaction with epithelial cells. Methods Structural characterization of G5G2.5 was performed by polyacrylamide gel electrophoresis, matrix-assisted laser desorption time-of-flight mass spectrometry, and microscopic techniques; their hydrodynamic size and Z-potential was also determined. Cellular uptake by human epidermal keratinocytes, colon adenocarcinoma, and epidermal melanoma (SK-Mel-28) cells was determined by flow cytometry. Cytotoxicity was determined by mitochondrial activity, lactate dehydrogenase release, glutathione depletion, and apoptosis/necrosis measurement. Results The resultant 60%–67% saturated shell, 87,000-dalton G5G2.5 (mean molecular weight) interacted with cells in a significantly different fashion in comparison to their building blocks and to its closest counterpart, PAMAM G6.5. After being actively taken up by epithelial cells, G5G2.5 caused cytotoxicity only on SK-Mel-28 cells, including depletion of intracellular glutathione and fast necrosis that was manifested above 5 μM G5

  17. Galactic Diffuse Gamma Ray Emission Is Greater than 10 Gev

    NASA Technical Reports Server (NTRS)

    Hunter, Stanley D.; White, Nicholas E. (Technical Monitor)

    2000-01-01

    AGILE and Gamma-ray Large Area Telescope (GLAST) are the next high-energy gamma-ray telescopes to be flown in space. These instruments will have angular resolution about 5 times better than Energetic Gamma-Ray Experiment Telescope (EGRET) above 10 GeV and much larger field of view. The on-axis effective area of AGILE will be about half that of EGRET, whereas GLAST will have about 6 times greater effective area than EGRET. The capabilities of ground based very high-energy telescopes are also improving, e.g. Whipple, and new telescopes, e.g. Solar Tower Atmospheric Cerenkov Effect Experiment (STACEE), Cerenkov Low Energy Sampling and Timing Experiment (CELESTE), and Mars Advanced Greenhouse Integrated Complex (MAGIC) are expected to have low-energy thresholds and sensitivities that will overlap the GLAST sensitivity above approximately 10 GeV. In anticipation of the results from these new telescopes, our current understanding of the galactic diffuse gamma-ray emission, including the matter and cosmic ray distributions is reviewed. The outstanding questions are discussed and the potential of future observations with these new instruments to resolve these questions is examined.

  18. Source sector and region contributions to BC and PM2.5 in Central Asia

    DOE PAGESBeta

    Kulkarni, S.; Sobhani, N.; Miller-Schulze, J. P.; Shafer, M. M.; Schauer, J. J.; Solomon, P. A.; Saide, P. E.; Spak, S. N.; Cheng, Y. F.; Denier van der Gon, H. A. C.; et al

    2015-02-18

    pollutants. Aerosols at these sites are shown to reflect dust, biomass burning, and anthropogenic sources from Europe; South, East, and Central Asia; and Russia depending on the time period. Simulations for a reference 2030 emission scenario based on pollution abatement measures already committed to in current legislation show that PM2.5 and BC concentrations in the region increase, with BC growing more than PM2.5 on a relative basis. This suggests that both the health impacts and the climate warming associated with these particles may increase over the next decades unless additional control measures are taken. The importance of observations in CA to help characterize the changes that are rapidly taking place in the region are discussed.« less

  19. An integrated PM2.5 source apportionment study: Positive Matrix Factorisation vs. the chemical transport model CAMx

    NASA Astrophysics Data System (ADS)

    Bove, M. C.; Brotto, P.; Cassola, F.; Cuccia, E.; Massabò, D.; Mazzino, A.; Piazzalunga, A.; Prati, P.

    2014-09-01

    Receptor and Chemical Transport Models are commonly used tools in source apportionment studies, even if different expertise is required. We describe an experiment using both approaches to apportion the PM2.5 (i.e., particulate matter with aerodynamic diameters below 2.5 μm) sources in the city of Genoa (Italy). A sampling campaign was carried out to collect PM2.5 samples daily for approximately six month during 2011 in three sites. The subsequent compositional analyses included the speciation of elements, major ions and both organic and elemental carbon; these data produced a large database for receptor modelling through Positive Matrix Factorisation (PMF). In the same period, a meteorological and air quality modelling system was implemented based on the mesoscale numerical weather prediction model WRF and the chemical transport model CAMx to obtain meteorological and pollutant concentrations up to a resolution of 1.1 km. The source apportionment was evaluated by CAMx over the same period that was used for the monitoring campaign using the Particulate Source Apportionment Technology tool. Even if the source categorisations were changed (i.e., groups of time-correlated compounds in PMF vs. activity categories in CAMx), the PM2.5 source apportionment by PMF and CAMx produced comparable results. The different information provided by the two approaches (e.g., real-world factor profile by PMF and apportionment of a secondary aerosol by CAMx) was used jointly to elucidate the composition and origin of PM2.5 and to develop a more general methodology. When studying the primary and secondary components of PM, the main anthropogenic sources in the area were road transportation, energy production/industry and maritime emissions, accounting for 40%-50%, 20%-30% and 10%-15%, of PM2.5, respectively.

  20. Photoionization mass spectrometric measurements of initial reaction pathways in low-temperature oxidation of 2,5-dimethylhexane

    SciTech Connect

    Rotavera, Brandon; Zádor, Judit; Welz, Oliver; Sheps, Leonid; Scheer, Adam M.; Savee, John D.; Akbar Ali, Mohamad; Lee, Taek Soon; Simmons, Blake A.; Osborn, David L.; Violi, Angela; Taatjes, Craig A.

    2014-09-19

    The product formation from R + O2 reactions relevant to low-temperature autoignition chemistry was studied for 2,5-dimethylhexane, a symmetrically branched octane isomer, at 550 and 650 K using Cl-atom initiated oxidation and multiplexed photoionization mass spectrometry (MPIMS). The interpretation of time- and photon-energy-resolved mass spectra led to three specific results important to characterizing the initial oxidation steps: (1) quantified isomer-resolved branching ratios for HO2 + alkene channels; (2) 2,2,5,5-tetramethyltetrahydrofuran is formed in substantial yield from addition of O2 to tertiary 2,5-dimethylhex-2-yl followed by isomerization of the resulting ROO adduct to tertiary hydroperoxyalkyl (QOOH) and exhibits a positive dependence on temperature over the range covered leading to a higher flux relative to aggregate cyclic ether yield. The higher relative flux is explained by a 1,5-hydrogen atom shift reaction that converts the initial primary alkyl radical (2,5-dimethylhex-1-yl) to the tertiary alkyl radical 2,5-dimethylhex-2-yl, providing an additional source of tertiary alkyl radicals. Furthermore, quantum-chemical and master-equation calculations of the unimolecular decomposition of the primary alkyl radical reveal that isomerization to the tertiary alkyl radical is the most favorable pathway, and is favored over O2-addition at 650 K under the conditions herein. The isomerization pathway to tertiary alkyl radicals therefore contributes an additional mechanism to 2,2,5,5-tetramethyltetrahydrofuran formation; (3) carbonyl species (acetone, propanal, and methylpropanal) consistent with β-scission of QOOH radicals were formed in significant yield, indicating unimolecular QOOH decomposition into carbonyl + alkene + OH.

  1. Photoionization mass spectrometric measurements of initial reaction pathways in low-temperature oxidation of 2,5-dimethylhexane

    DOE PAGESBeta

    Rotavera, Brandon; Zádor, Judit; Welz, Oliver; Sheps, Leonid; Scheer, Adam M.; Savee, John D.; Akbar Ali, Mohamad; Lee, Taek Soon; Simmons, Blake A.; Osborn, David L.; et al

    2014-09-19

    The product formation from R + O2 reactions relevant to low-temperature autoignition chemistry was studied for 2,5-dimethylhexane, a symmetrically branched octane isomer, at 550 and 650 K using Cl-atom initiated oxidation and multiplexed photoionization mass spectrometry (MPIMS). The interpretation of time- and photon-energy-resolved mass spectra led to three specific results important to characterizing the initial oxidation steps: (1) quantified isomer-resolved branching ratios for HO2 + alkene channels; (2) 2,2,5,5-tetramethyltetrahydrofuran is formed in substantial yield from addition of O2 to tertiary 2,5-dimethylhex-2-yl followed by isomerization of the resulting ROO adduct to tertiary hydroperoxyalkyl (QOOH) and exhibits a positive dependence on temperaturemore » over the range covered leading to a higher flux relative to aggregate cyclic ether yield. The higher relative flux is explained by a 1,5-hydrogen atom shift reaction that converts the initial primary alkyl radical (2,5-dimethylhex-1-yl) to the tertiary alkyl radical 2,5-dimethylhex-2-yl, providing an additional source of tertiary alkyl radicals. Furthermore, quantum-chemical and master-equation calculations of the unimolecular decomposition of the primary alkyl radical reveal that isomerization to the tertiary alkyl radical is the most favorable pathway, and is favored over O2-addition at 650 K under the conditions herein. The isomerization pathway to tertiary alkyl radicals therefore contributes an additional mechanism to 2,2,5,5-tetramethyltetrahydrofuran formation; (3) carbonyl species (acetone, propanal, and methylpropanal) consistent with β-scission of QOOH radicals were formed in significant yield, indicating unimolecular QOOH decomposition into carbonyl + alkene + OH.« less

  2. Quantitative analysis on windblown dust concentrations of PM10 (PM2.5) during dust events in Mongolia

    NASA Astrophysics Data System (ADS)

    Jugder, Dulam; Shinoda, Masato; Kimura, Reiji; Batbold, Altangerel; Amarjargal, Danzansambuu

    2014-09-01

    Dust concentration, wind speed and visibility, measured at four sites in the Gobi Desert and at a site in the steppe zone of Mongolia over a period of 4.5 years (January 2009 to May 2013), have been analyzed for their relationships, their effects on visibility, and for an estimate of the threshold wind necessary for dust emission in the region. Based on quantitative analysis on measurements, we evaluated that dust emission concentrations of 41-61 (20-24) μg m-3 of PM10 (PM2.5) are as the criterion between normal and hazy atmospheric conditions. With the arrival of dust events, wind-borne soil particulate matter (PM10, PM2.5) that originates in the Gobi Desert is changed dramatically. PM10 (PM2.5) concentrations increase by at least double or by several tens of times during severe dust events in comparison with the normal atmospheric condition. Ratio (PM2.5/PM10) between monthly means of PM10 and PM2.5 concentrations showed that anthropogenic particles were dominant in the ambient air of province centers in cool months (November to February). Threshold values of the onset of dust events were determined for PM10 (PM2.5) concentrations. According to the definition of dust storms, dust concentrations of PM10 corresponding to visibility of 1 km or less were determined at sites in the Gobi Desert and the steppe region. The threshold wind speeds during days with dust events were estimated at four sites in the Gobi Desert and compared each other. The threshold wind was higher at Sainshand and its cause might be due to smaller silt and clay fractions of soil.

  3. Airborne concentrations of PM(2.5) and diesel exhaust particles on Harlem sidewalks: a community-based pilot study.

    PubMed Central

    Kinney, P L; Aggarwal, M; Northridge, M E; Janssen, N A; Shepard, P

    2000-01-01

    Residents of the dense urban core neighborhoods of New York City (NYC) have expressed increasing concern about the potential human health impacts of diesel vehicle emissions. We measured concentrations of particulate matter [less than/equal to] 2.5 micro in aerodynamic diameter (PM(2.5)) and diesel exhaust particles (DEP) on sidewalks in Harlem, NYC, and tested whether spatial variations in concentrations were related to local diesel traffic density. Eight-hour (1000-1800 hr) air samples for PM(2.5 )and elemental carbon (EC) were collected for 5 days in July 1996 on sidewalks adjacent to four geographically distinct Harlem intersections. Samples were taken using portable monitors worn by study staff. Simultaneous traffic counts for diesel trucks, buses, cars, and pedestrians were carried out at each intersection on [Greater/equal to] 2 of the 5 sampling days. Eight-hour diesel vehicle counts ranged from 61 to 2,467 across the four sites. Mean concentrations of PM(2.5) exhibited only modest site-to-site variation (37-47 microg/m(3)), reflecting the importance of broader regional sources of PM(2.5). In contrast, EC concentrations varied 4-fold across sites (from 1.5 to 6 microg/m(3)), and were associated with bus and truck counts on adjacent streets and, at one site, with the presence of a bus depot. A high correlation (r = 0.95) was observed between EC concentrations measured analytically and a blackness measurement based on PM(2.5) filter reflectance, suggesting the utility of the latter as a surrogate measure of DEP in future community-based studies. These results show that local diesel sources in Harlem create spatial variations in sidewalk concentrations of DEP. The study also demonstrates the feasibility of a new paradigm for community-based research involving full and active partnership between academic scientists and community-based organizations. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:10706526

  4. Chemical composition and sources of PM2.5 and TSP collected at Qinghai Lake during summertime

    NASA Astrophysics Data System (ADS)

    Zhang, Ningning; Cao, Junji; Liu, Suixin; Zhao, ZhuZi; Xu, Hongmei; Xiao, Shun

    2014-03-01

    PM2.5 and total suspended particulate (TSP) samples were collected from June to September 2010 at Qinghai Lake, northeastern Tibetan Plateau. The concentrations of major water-soluble ions, 10 elements, elemental carbons (ECs) and organic carbons (OCs) were quantified. Mass concentrations of PM2.5 and TSP were 21.27 ± 10.70 μg m- 3 and 41.47 ± 20.25 μg m- 3, respectively, and the mean ratio of PM2.5/TSP was 0.51. The greatest anion and cation in both PM2.5 and TSP samples were SO42 - and Ca2 +, respectively. Crustal elements, such as Ca, Fe and K, were the main elements in our aerosol samples, and their enrichment factors (EFs) were lower than 10. EFs for Pb, As, and Zn were greater than 10, indicating that they were influenced by anthropogenic sources. EC concentrations were 0.33 ± 0.17 μg m- 3 and 0.47 ± 0.28 μg m- 3, whereas OC concentrations were 1.49 ± 0.63 μg m- 3 and 2.30 ± 0.95 μg m- 3 in PM2.5 and TSP, respectively. Based on the calculated ratios of EC/TC and K+/EC, most of the ECs were found to be related to biomass burning emissions. Because of the pollution from local sources, the ratios of OC/EC were 4.77 ± 1.32 and 5.23 ± 1.39 in PM2.5 and TSP, respectively, which were lower than those of other remote sites. Salt particles produced by the salty lake reacted with acid gases and caused most of the nitrates and a small fraction of sulfate to be distributed in coarse mode; Cl deficit was also observed in our aerosol samples. Results of backward trajectories and correlation analysis show that the concentrations of SO4 2-, OCs, As, Pb, and Zn, were influenced by the long-distance transport from eastern China.

  5. Urban air pollution: a representative survey of PM(2.5) mass concentrations in six Brazilian cities.

    PubMed

    de Miranda, Regina Maura; de Fatima Andrade, Maria; Fornaro, Adalgiza; Astolfo, Rosana; de Andre, Paulo Afonso; Saldiva, Paulo

    2012-03-01

    In urban areas of Brazil, vehicle emissions are the principal source of fine particulate matter (PM(2.5)). The World Health Organization air quality guidelines state that the annual mean concentration of PM(2.5) should be below 10 μg m(-3). In a collaboration of Brazilian institutions, coordinated by the University of São Paulo School of Medicine and conducted from June 2007 to August 2008, PM(2.5) mass was monitored at sites with high traffic volumes in six Brazilian state capitals. We employed gravimetry to determine PM(2.5) mass concentrations, reflectance to quantify black carbon concentrations, X-ray fluorescence to characterize elemental composition, and ion chromatography to determine the composition and concentrations of anions and cations. Mean PM(2.5) concentrations and proportions of black carbon (BC) in the cities of São Paulo, Rio de Janeiro, Belo Horizonte, Curitiba, Recife, and Porto Alegre were 28.1 ± 13.6 μg m(-3) (38% BC), 17.2 ± 11.2 μg m(-3) (20% BC), 14.7 ± 7.7 μg m(-3) (31% BC), 14.4 ± 9.5 μg m(-3) (30% BC), 7.3 ± 3.1 μg m(-3) (26% BC), and 13.4 ± 9.9 μg m(-3) (26% BC), respectively. Sulfur and minerals (Al, Si, Ca, and Fe), derived from fuel combustion and soil resuspension, respectively, were the principal elements of the PM(2.5) mass. We discuss the long-term health effects for each metropolitan region in terms of excess mortality risk, which translates to greater health care expenditures. This information could prove useful to decision makers at local environmental agencies. PMID:22408694

  6. Using Machine Learning to Estimate Global PM2.5 for Environmental Health Studies

    PubMed Central

    Lary, D. J.; Lary, T.; Sattler, B.

    2015-01-01

    With the increasing awareness of health impacts of particulate matter, there is a growing need to comprehend the spatial and temporal variations of the global abundance of ground-level airborne particulate matter (PM2.5). Here we use a suite of remote sensing and meteorological data products together with ground based observations of PM2.5 from 8,329 measurement sites in 55 countries taken between 1997 and 2014 to train a machine learning algorithm to estimate the daily distributions of PM2.5 from 1997 to the present. We demonstrate that the new PM2.5 data product can reliably represent global observations of PM2.5 for epidemiological studies. An analysis of Baltimore schizophrenia emergency room admissions is presented in terms of the levels of ambient pollution. PM2.5 appears to have an impact on some aspects of mental health. PMID:26005352

  7. SAMPLING, ANALYSIS, AND PROPERTIES OF PRIMARY PM-2.5: APPLICATION TO COAL-FIRED UTILITY BOILERS

    SciTech Connect

    Allen L. Robinson; Spyros N. Pandis; Eric Lipsky; Charles Stainer; Natalie Anderson; Satoshi Takahama; Sarah Rees

    2003-02-01

    A dilution sampler was used to examine the effects of dilution ratio and residence time on the particulate emissions from a pilot-scale pulverized coal combustor. Measurements include the particle size distribution from 0.003 to 2.5 {micro}m, PM{sub 2.5} mass emission rate and PM2.5 composition (OC/EC, major ions, and elemental). Hot filter samples were also collected simultaneously in order to compare the dilution sampler measurement with standard stack sampling methodologies such as EPA Method 5. Measurements were made both before and after the bag-house, the particle control device used on the coal combustor. Measurements were made with three different coal types and a coal-biomass blend. The residence time and dilution ratio do not influence the PM{sub 2.5} mass emission rate, but have a significant effect on the size distribution and total number emissions. Measurements made before the bag-house showed increasing the residence time dramatically decreases the total particle number concentration, and shifts the particle mass to larger sizes. The effects of residence time can be explained quantitatively by the coagulation of the emitted particles. Measurements made after the bag-house were not affected by coagulation due to the lower concentration of particles. Nucleation of sulfuric acid vapor within the dilution was an important source of ultrafine particles. This nucleation is strongly a function of dilution ratio because of the competition between condensation and nucleation. At low dilution ratios condensation dominates and little nucleation is observed; increasing the dilution ratio promotes nucleation because of the corresponding decrease in available surface area per unit volume for condensation. No nucleation was observed after the bag house where conditions greatly favor nucleation over condensation; we suspect that the bag house removed the SO{sub 3} in the flue gas. Exhaust SO{sub 3} levels were not measured during these experiments. Dilution caused

  8. Ambient temperature enhanced acute cardiovascular-respiratory mortality effects of PM2.5 in Beijing, China

    NASA Astrophysics Data System (ADS)

    Li, Yi; Ma, Zhiqiang; Zheng, Canjun; Shang, Yu

    2015-12-01

    Studies have shown that temperature could modify the effect of ambient fine particles on mortality risk. In assessing air pollution effects, temperature is usually considered as a confounder. However, ambient temperature can alter people's physiological response to air pollution and might "modify" the impact of air pollution on health outcomes. This study investigated the interaction between daily PM2.5 and daily mean temperature in Beijing, China, using data for the period 2005-2009. Bivariate PM2.5-temperature response surfaces and temperature-stratified generalized additive model (GAM) were applied to study the effect of PM2.5 on cardiovascular, respiratory mortality, and total non-accidental mortality across different temperature levels. We found that low temperature could significantly enhance the effect of PM2.5 on cardiovascular mortality. For an increase of 10 μg/m3 in PM2.5 concentration in the lowest temperature range (-9.7˜2.6 °C), the relative risk (RR) of cardiovascular mortality increased 1.27 % (95 % CI 0.38˜2.17 %), which was higher than that of the whole temperature range (0.59 %, 95 % CI 0.22-1.16 %). The largest effect of PM2.5 on respiratory mortality appeared in the high temperature range. For an increase of 10 μg/m3 in PM2.5 concentration, RR of respiratory mortality increased 1.70 % (95 % CI 0.92˜3.33 %) in the highest level (23.50˜31.80 °C). For the total non-accidental mortality, significant associations appeared only in low temperature levels (-9.7˜2.6 °C): for an increase of 10 μg/m3 in current day PM2.5 concentration, RR increased 1.27 % (95 % CI 0.46˜2.00 %) in the lowest temperature level. No lag effect was observed. The results suggest that in air pollution mortality time series studies, the possibility of an interaction between air pollution and temperature should be considered.

  9. Characteristics of concentrations and water-soluble inorganic ions in PM2.5 in Handan City, Hebei province, China

    NASA Astrophysics Data System (ADS)

    Meng, C. C.; Wang, L. T.; Zhang, F. F.; Wei, Z.; Ma, S. M.; Ma, X.; Yang, J.

    2016-05-01

    In order to explore the spatial, temporal, and chemical characteristics of fine particulate matter (PM2.5) pollution in Handan city, China, a comprehensive dataset including continuous online observations at four air quality monitoring stations in 2013 and 2014, and the concentrations of water-soluble inorganic ions (WSII) (NO3-, SO42 -, NH4+, Cl-, Na+, Mg2 +, K+, Ca2 +) in PM2.5 samples collected in four representative seasons in 2013 and 2014 are analyzed in this study. And the principal component analysis (PCA) method is applied to identify the source of WSII in Handan. Our results indicate that PM2.5 concentration decreased from 139.4 μg/m3 in 2013 to 116.0 μg/m3 in 2014 on annual average. Spatial variations of PM2.5 mass are not pronounced, indicating that PM2.5 is nearly evenly spread over the study area. The seasonal variations of PM2.5 concentration are significant, normally with 1.7 to 2.4 times higher in winter than in summer. The concentrations of TWSII (total water-soluble inorganic ions) remain relatively stable in two years, with annual averages of 63.1 μg/m3 in 2013 and 57.2 μg/m3 in 2014. SNA (SO42 -, NO3-, NH4+) dominates in the TWSII, accounting for ~ 87% of the TWSII. Similar to PM2.5, WSII exhibits obvious seasonal variations with higher concentrations in autumn and winter, lower in spring and summer. PM2.5 samples are acidic in spring, summer and autumn of 2013, while in winter of 2013 and all seasons of 2014, they are alkaline. SO42 -, NO3- are formed mainly through homogeneous reactions, heterogeneous reactions also exist in winter. Finally, the major sources of WSII in Handan are identified as the mixture of secondary origin, coal combustion, biomass burning (46.1%), dust sources (25.8%), and motor vehicle (12.3%).

  10. Potential application of VIIRS Day/Night Band for monitoring nighttime surface PM2.5 air quality from space

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Aegerter, Clint; Xu, Xiaoguang; Szykman, James J.

    2016-01-01

    A pilot study is conducted to illustrate the potential of using radiance data collected by the Day/Night Band (DNB) of the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership (S-NPP) satellite for particulate matter (PM) air quality monitoring at night. The study focuses on the moonless and cloudless nights in Atlanta, Georgia during August-October 2012. We show with radiative transfer calculations that DNB at night is sensitive to the change of aerosols and much less sensitive to the change of water vapor in the atmosphere illuminated by common outdoor light bulbs at the surface. We further show both qualitatively that the contrast of DNB images can indicate the change of air quality at the urban scale, and quantitatively that change of light intensity during the night (as characterized by VIIRS DNB) reflects the change of surface PM2.5. Compared to four meteorological variables (u and v components of surface wind speed, surface pressure, and columnar water vapor amount) that can be obtained from surface measurements, the DNB light intensity is the only variable that shows either the largest or second largest correlation with surface PM2.5 measured at 5 different sites. A simple multivariate regression model with consideration of the change of DNB light intensity can yield improved estimate of surface PM2.5 as compared to the model with consideration of meteorological variables only. Cross validation of this DNB-based regression model shows that the estimated surface PM2.5 concentration has nearly no bias and a linear correlation coefficient (R) of 0.67 with respect to the corresponding hourly observed surface PM2.5 concentration. Furthermore, ground-based observations support that surface PM2.5 concentration at the VIIRS night overpass (˜1:00 am local) time is representative of daily-mean PM2.5 air quality (R = 0.82 and mean bias of -0.1 μg m-3). While the potential appears promising, mapping surface PM2.5 from

  11. 7 CFR 2.5 - Order in which officers of the Department shall act as Secretary.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Order in which officers of the Department shall act as Secretary. 2.5 Section 2.5 Agriculture Office of the Secretary of Agriculture DELEGATIONS OF AUTHORITY BY THE SECRETARY OF AGRICULTURE AND GENERAL OFFICERS OF THE DEPARTMENT General § 2.5 Order in which officers of the Department shall act...

  12. NARSTO Texas PM2.5 Sampling and Analysis Study 1997-1998

    Atmospheric Science Data Center

    2014-04-25

    NARSTO Texas PM2.5 Sampling and Analysis Study 1997-1998 Project Title:  ... Instrument:  DRI MEDVOL Location:  Texas Spatial Coverage:  (27.8069 - 32.7742) (-106.4828 - ...   Order Data Guide Documents:  Texas PM2.5 Guide Texas PM2.5 Final Report  Tropp et al, 1998 ...

  13. Fracture characteristics, microstructure, and tissue reaction of Ti-5Al-2.5Fe for orthopedic surgery

    NASA Astrophysics Data System (ADS)

    Niinomi, Mitsuo; Kobayashi, Toshiro; Toriyama, Osamu; Kawakami, Noriaki; Ishida, Yoshihito; Matsuyama, Yukihiro

    1996-12-01

    The microstructure of Ti-5Al-2.5Fe, which is expected to be used widely as an implant material not only for artificial hip joints but also for instrumentations of scoliosis surgery, was variously changed by heat treatments. The effect of the microstructure on mechanical properties, fracture toughness, and rotating-bending fatigue strength in the air and simulated body environment, that is, Ringer’s solution, was then investigated. Furthermore, the effect of the living body environment on mechanical properties and fracture toughness in Ti-5Al-2.5Fe were investigated on the specimens implanted into rabbit for about 11 months. The data of Ti-5Al-2.5Fe were compared with those of Ti-6Al-4V ELI, which has been used as an implant material mainly for artificial hip joints, and SUS 316L, which has been used as an implant material for many parts, including the instrumentation of scoliosis surgery. The equiaxed α structure, which is formed by annealing at a temperature below β transus, gives the best balance of strength and ductility in Ti-5Al-2.5Fe. The coarse Widmanstätten α structure, which is formed by solutionizing over β transus followed by air cooling and aging, gives the greatest fracture toughness in Ti-5Al-2.5Fe. This trend is similar to that reported in Ti-6Al-4V ELI. The rotating-bending fatigue strength is the greatest in the equiaxed α structure, which is formed by solutionizing below β transus followed by air cooling and aging in Ti-5Al-2.5Fe. Ti-5Al-2.5Fe exhibits much greater rotating-bending fatigue strength compared with SUS 316L, and equivalent rotating-bending fatigue strength to that of Ti-6Al-4V ELI in both the air and simulated body environments. The rotating-bending fatigue strength of SUS 316L is degraded in the simulated body environment. The corrosion fatigue, therefore, occurs in SUS 316L in the simulated body environment. Fatigue strength of Ti-5Al-2.5Fe in the simulated body environment is degraded by lowering oxygen content in the

  14. Spectroscopic properties, NLO, HOMO-LUMO and NBO analysis of 2,5-Lutidine.

    PubMed

    Govindarajan, M; Karabacak, M

    2012-10-01

    In this work, FT-IR and FT-Raman spectra of 2,5-Lutidine (C(7)H(9)N) have been reported in the regions 4000-400 cm(-1) and 3500-100 cm(-1), respectively. Density functional theory (DFT) has been used to calculate the optimized geometrical parameters, atomic charges, vibrational wavenumbers and intensity of the vibrational bands. The vibrational frequencies have been calculated and scaled values are compared with experimental FT-IR and FT-Raman spectra. The structure optimizations and normal coordinate force field calculations are based on HF and B3LYP methods with 6-311++G(d,p) basis set. The complete vibrational assignments of wavenumbers have been made on the basis of potential energy distribution (PED). The results of the calculation shows excellent agreement between experimental and calculated frequencies in B3LYP/6-311++G(d,p) basis set. The optimized geometric parameters were compared with experimental values of 2,5-Lutidine. A study on the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. Besides, frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) and thermodynamic properties were performed. Mulliken charges and NBOs of the title molecule were also calculated and interpreted. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. The dipole moment, linear polarizability and first hyperpolarizability values were also computed. PMID:22722076

  15. Spatial Variation of the Relationship between PM2.5 Concentrations and Meteorological Parameters in China

    PubMed Central

    Lin, Gang; Fu, Jingying; Jiang, Dong; Wang, Jianhua; Wang, Qiao; Dong, Donglin

    2015-01-01

    Epidemiological studies around the world have reported that fine particulate matter (PM2.5) is closely associated with human health. The distribution of PM2.5 concentrations is influenced by multiple geographic and socioeconomic factors. Using a remote-sensing-derived PM2.5 dataset, this paper explores the relationship between PM2.5 concentrations and meteorological parameters and their spatial variance in China for the period 2001–2010. The spatial variations of the relationships between the annual average PM2.5, the annual average precipitation (AAP), and the annual average temperature (AAT) were evaluated using the Geographically Weighted Regression (GWR) model. The results indicated that PM2.5 had a strong and stable correlation with meteorological parameters. In particular, PM2.5 had a negative correlation with precipitation and a positive correlation with temperature. In addition, the relationship between the variables changed over space, and the strong negative correlation between PM2.5 and the AAP mainly appeared in the warm temperate semihumid region and northern subtropical humid region in 2001 and 2010, with some localized differences. The strong positive correlation between the PM2.5 and the AAT mainly occurred in the mid-temperate semiarid region, the humid, semihumid, and semiarid warm temperate regions, and the northern subtropical humid region in 2001 and 2010. PMID:26295046

  16. Spatial Variation of the Relationship between PM 2.5 Concentrations and Meteorological Parameters in China.

    PubMed

    Lin, Gang; Fu, Jingying; Jiang, Dong; Wang, Jianhua; Wang, Qiao; Dong, Donglin

    2015-01-01

    Epidemiological studies around the world have reported that fine particulate matter (PM2.5) is closely associated with human health. The distribution of PM2.5 concentrations is influenced by multiple geographic and socioeconomic factors. Using a remote-sensing-derived PM2.5 dataset, this paper explores the relationship between PM2.5 concentrations and meteorological parameters and their spatial variance in China for the period 2001-2010. The spatial variations of the relationships between the annual average PM2.5, the annual average precipitation (AAP), and the annual average temperature (AAT) were evaluated using the Geographically Weighted Regression (GWR) model. The results indicated that PM2.5 had a strong and stable correlation with meteorological parameters. In particular, PM2.5 had a negative correlation with precipitation and a positive correlation with temperature. In addition, the relationship between the variables changed over space, and the strong negative correlation between PM2.5 and the AAP mainly appeared in the warm temperate semihumid region and northern subtropical humid region in 2001 and 2010, with some localized differences. The strong positive correlation between the PM2.5 and the AAT mainly occurred in the mid-temperate semiarid region, the humid, semihumid, and semiarid warm temperate regions, and the northern subtropical humid region in 2001 and 2010. PMID:26295046

  17. Spatial analysis of MODIS aerosol optical depth, PM2.5, and chronic coronary heart disease

    PubMed Central

    Hu, Zhiyong

    2009-01-01

    Background Numerous studies have found adverse health effects of acute and chronic exposure to fine particulate matter (PM2.5). Air pollution epidemiological studies relying on ground measurements provided by monitoring networks are often limited by sparse and unbalanced spatial distribution of the monitors. Studies have found correlations between satellite aerosol optical depth (AOD) and PM2.5 in some land regions. Satellite aerosol data may be used to extend the spatial coverage of PM2.5 exposure assessment. This study was to investigate correlation between PM2.5 and AOD in the conterminous USA, to derive a spatially complete PM2.5 surface by merging satellite AOD data and ground measurements based on the potential correlation, and to examine if there is an association of coronary heart disease with PM2.5. Results Years 2003 and 2004 daily MODIS (Moderate Resolution Imaging Spectrometer) Level 2 AOD images were collated with US EPA PM2.5 data covering the conterminous USA. Pearson's correlation analysis and geographically weighted regression (GWR) found that the relationship between PM2.5 and AOD is not spatially consistent across the conterminous states. The average correlation is 0.67 in the east and 0.22 in the west. GWR predicts well in the east and poorly in the west. The GWR model was used to derive a PM2.5 grid surface using the mean AOD raster calculated using the daily AOD data (RMSE = 1.67 μg/m3). Fitting of a Bayesian hierarchical model linking PM2.5 with age-race standardized mortality rates (SMRs) of chronic coronary heart disease found that areas with higher values of PM2.5 also show high rates of CCHD mortality: = 0.802, posterior 95% Bayesian credible interval (CI) = (0.386, 1.225). Conclusion There is a spatial variation of the relationship between PM2.5 and AOD in the conterminous USA. In the eastern USA where AOD correlates well with PM2.5, AOD can be merged with ground PM2.5 data to derive a PM2.5 surface for epidemiological study. The study

  18. Regulation of alternative polyadenylation by Nkx2-5 and Xrn2 during mouse heart development.

    PubMed

    Nimura, Keisuke; Yamamoto, Masamichi; Takeichi, Makiko; Saga, Kotaro; Takaoka, Katsuyoshi; Kawamura, Norihiko; Nitta, Hirohisa; Nagano, Hiromichi; Ishino, Saki; Tanaka, Tatsuya; Schwartz, Robert J; Aburatani, Hiroyuki; Kaneda, Yasufumi

    2016-01-01

    Transcription factors organize gene expression profiles by regulating promoter activity. However, the role of transcription factors after transcription initiation is poorly understood. Here, we show that the homeoprotein Nkx2-5 and the 5'-3' exonuclease Xrn2 are involved in the regulation of alternative polyadenylation (APA) during mouse heart development. Nkx2-5 occupied not only the transcription start sites (TSSs) but also the downstream regions of genes, serving to connect these regions in primary embryonic cardiomyocytes (eCMs). Nkx2-5 deficiency affected Xrn2 binding to target loci and resulted in increases in RNA polymerase II (RNAPII) occupancy and in the expression of mRNAs with long 3'untranslated regions (3' UTRs) from genes related to heart development. siRNA-mediated suppression of Nkx2-5 and Xrn2 led to heart looping anomaly. Moreover, Nkx2-5 genetically interacts with Xrn2 because Nkx2-5(+/-)Xrn2(+/-), but neither Nkx2-5(+/-)nor Xrn2(+/-), newborns exhibited a defect in ventricular septum formation, suggesting that the association between Nkx2-5 and Xrn2 is essential for heart development. Our results indicate that Nkx2-5 regulates not only the initiation but also the usage of poly(A) sites during heart development. Our findings suggest that tissue-specific transcription factors is involved in the regulation of APA. PMID:27331609

  19. Satellite-derived high resolution PM2.5 concentrations in Yangtze River Delta Region of China using improved linear mixed effects model

    NASA Astrophysics Data System (ADS)

    Ma, Zongwei; Liu, Yang; Zhao, Qiuyue; Liu, Miaomiao; Zhou, Yuanchun; Bi, Jun

    2016-05-01

    Satellite remotely sensed aerosol optical depth (AOD) provides an effective way to fill the spatial and temporal gaps left by ground PM2.5 monitoring network. Previous studies have established robust advanced statistical models to estimate PM2.5 using AOD data in China. However, their coarse resolutions (∼10 km or greater) of PM2.5 estimations are not enough to support the health effect studies at urban scales. In this study, 3 km AOD data from Moderate Resolution Imaging Spectroradiometer (MODIS) collection 6 products were used to estimate the high resolution PM2.5 concentrations in Yangtze Delta Region of China. We proposed a nested linear mixed effects (LME) model including nested month-, week-, and day-specific random effects of PM2.5-AOD relationships. Validation results show that the LME model only with day-specific random effects (non-nested model) used in previous studies has poor performance in the days without PM2.5-AOD matchups (the R2 of day-of-year-based cross validation (DOY-based CV) is 0.148). The results also show that our nested model cannot improve the performance of non-nested model in the days with PM2.5-AOD matchups (sample-based CV R2 = 0.671 for nested model vs. 0.661 for non-nested model), but can greatly improve the model performance beyond those days (DOY-based CV R2 = 0.339 for nested model vs. 0.148 for non-nested model). To further improve the model performance, we applied the "buffer models" (i.e., models fitted from datasets which ground PM2.5 were matched with the average AOD values within certain radius buffer zones of gridded PM2.5 data) on the 3 km AOD data since the "buffer models" has more days with PM2.5-AOD matchups and can provide more day-specific relationships. The results of this study show that 3 km MODIS C6 AOD data can be used to estimate PM2.5 concentrations and can provide more detailed spatial information for urban scale studies. The application of our nested LME model can greatly improve the accuracy of 3

  20. A Querying Method over RDF-ized Health Level Seven v2.5 Messages Using Life Science Knowledge Resources

    PubMed Central

    2016-01-01

    Background Health level seven version 2.5 (HL7 v2.5) is a widespread messaging standard for information exchange between clinical information systems. By applying Semantic Web technologies for handling HL7 v2.5 messages, it is possible to integrate large-scale clinical data with life science knowledge resources. Objective Showing feasibility of a querying method over large-scale resource description framework (RDF)-ized HL7 v2.5 messages using publicly available drug databases. Methods We developed a method to convert HL7 v2.5 messages into the RDF. We also converted five kinds of drug databases into RDF and provided explicit links between the corresponding items among them. With those linked drug data, we then developed a method for query expansion to search the clinical data using semantic information on drug classes along with four types of temporal patterns. For evaluation purpose, medication orders and laboratory test results for a 3-year period at the University of Tokyo Hospital were used, and the query execution times were measured. Results Approximately 650 million RDF triples for medication orders and 790 million RDF triples for laboratory test results were converted. Taking three types of query in use cases for detecting adverse events of drugs as an example, we confirmed these queries were represented in SPARQL Protocol and RDF Query Language (SPARQL) using our methods and comparison with conventional query expressions were performed. The measurement results confirm that the query time is feasible and increases logarithmically or linearly with the amount of data and without diverging. Conclusions The proposed methods enabled query expressions that separate knowledge resources and clinical data, thereby suggesting the feasibility for improving the usability of clinical data by enhancing the knowledge resources. We also demonstrate that when HL7 v2.5 messages are automatically converted into RDF, searches are still possible through SPARQL without